Any class can be open ended by multiclassing, that doesn't make it good. Eldritch Knight is a worse hexblade, not even a half caster like a paladin since it can't even get 5th level spells. Echo Knight is in an extra book made by someone not in Wizard's and it shows, because it actually has flavor.
PF2 is completely different to PF1, PF1 is closer to 5e than it is to PF2. Even multiclassing in PF2 is ridiculously easy and fun, without having to worry about accidentally making your character completely useless in battle.
PF2 is stricter? Since when? It has more options that 5e ever did, it is just better. Go learn PF2 instead of judging it from your experience with PF1 before preaching 5e like a fanboy/girl.
That would actually make someone in my table pass out, not even joking