Trans people must be very powerful, if the mere knowledge of their existence appears to be this dangerous to these ppl.

Aye. Knowing about the existence of trans people might cause a person to query a whole bunch of stuff about gender, and from that they might come to query many other norms and constructs.

Which to a conservative is about as threatening as it can possibly get. Or rather, the increased awareness in the general population that results from querying things is, and how that population might shape society in response. People who derive a sense of security and well-being from clearly defined roles and rules and hierarchies, even if those are enforced harshly against them, don't only fear that instability and worse conditions could come in the wake of major socio-political reforms - they fear it as an existential threat because without those clear roles & rules, etc., how will they themselves know how to be?

Though for the most part they're only having this grotesque hate-tantrum because their corporate overlords prefer it when they're distracted and emotional, and trans people are a particularly tiny minority to direct their attention at.