I understand what you're saying, and I understand where you're coming from. As I said I started tabletop gaming with D&D 3.5 and it's myriad rules and situational bonuses specifically designed to cover every imaginable situation. I took a long break from the hobby due to various distractions and other issues in my life shortly after 4e was released, which I looked at and was thoroughly uninterested with. When I came back to the hobby a few years ago and looked into 5e my immediate impression was "this is like 3.5 but designed to work with with smaller numbers and less of them so you don't spend 80% of combat composing nine variable algebraic equations to figure out what modifiers apply to each individual roll."

A lot of the "uncovered details" can be handled with a little bit of flexible thinking from the DM. If somebody wants to do literally anything that would be covered by the "Use Rope" skill, for example, you can probably just use Sleight of Hand instead. The only other things I could think of that skill might apply to would be lassoing something (use an attack roll, judgement call on if the character should be considered proficient) or identifying a complex knot as being commonly used to secure moorings by a specific navy/pirate crew/etc, which would just be History and add advantage if the PC has the Sailor background. I know that's a very specific situation, but my point is that there are a lot of specific rules to be looking up whenever any and every new situation arises because "PF2E has a rule for that!"

I'll grant you that anything having to do with operating a boat or ship is a big gap in rules, but most D&D players aren't looking for a hyper-specific reproduction of historical naval combat from the Hellenistic period or the Golden Age of Piracy. If that's what they wanted they'd be playing a non-roleplaying tabletop wargame designed to do exactly that. This ship is faster than that one. You have a ballista on board that can launch javelins or be rigged to sling pots of "Greek fire" type alchemical incendiary bombs, plus whatever weapons and spells your PCs have. If you don't kill enough of their crew or catch the ship ablaze to damage it sufficiently, they're going to catch up in X rounds. When they catch up they throw ropes to anchor the ships and board. You can chop the ropes and break away but that takes at least a full round to happen and they're already boarding your ship. Or they're just ramming you and jumping aboard. Damage is pretty much arbitrary as to the ship remaining seaworthy and either way you have bad guys on your boat. This means regular combat and if you fall off either boat you're going swimming. I don't need a five page chapter of rules to run this encounter. I have no interest in using a resource tracking system that works best as a spreadsheet to make sure my crew are properly provisioned and not getting scurvy, which causes a series of tiered penalties to my ship handling rolls based on how long they've gone untreated and how many of them have been failing their saves/checks against disease and by how much because that's not what people actually give a rat's ass about. They just want to fight pirates (or be pirates) with the skills and abilities on their character sheet plus maybe shoot some cannons and swing dramatically on a long rope from a crow's nest to the other ship so they can challenge it's captain to a duel. Yes, this approach requires five seconds of active thought rather than a minute of looking up a rule in the encyclopedia of all the other rules and explaining it to players who may well not have even read the actual rules at all. "Give me an athletics check, DC20 lands you right in front of the Captain, less you land somewhere else on the boat, below a 15 you take 1d6 fall damage and less than a 10 means you miss and go swimming." Instant swashbuckler swing and however it ends up that's going to be what the players remember about the fight and not how many more or fewer rounds the chase leading up to the fight would have taken if their navigation and sail handling rolls had been a few digits higher or lower.

I also don't like systems that give you a few basic mechanics and tell you that every situation imaginable is either a X, Y, or Z roll and experience points lets you add extra dice to your pool and the GM makes up completely arbitrary results based on how many fives and sixes you rolled. I actually believe that 5e is a happy middle ground. There are rules that can be at least loosely applied to general situations and a little bit of mental flexibility can allow a DM to call up one of those rules from memory to use.

I did learn all the minute details from 3.5 and regularly ran games with players who had never actually opened a rulebook. They told me what they wanted their character to do and I built them a sheet to match what they wanted. They described in game what they wanted to do and I told them what to roll and added all the modifiers myself. These days I don't have the time to spend entire lazy afternoons reading through rulebooks multiple times to be able to do that, and I don't want to stop the action every other turn to look up a new rule because somebody thought of something clever and there's a rule for that. And if you're using the system specifically because no matter what there's a rule for that then that means you should be using those rules whether you already know them all or are stopping to look them up. If you just improvise something on the fly to save time then you should not be playing a system specifically because it has all those rules and does not require any improvisation at all. So I don't want that level of detail in a game system.

Yeah, you don't try teaching someone calculus if they still haven't mastered basic algebra. There's also my opinion about whether you actually need to bother learning "calculus" just to use eight different rules applied to attacking a single adversary in one round of combat in the first place, rather than just rolling multiple attacks and maybe adding in one or two class/subclass features.