My first guess would be dried out caps. A weak cap or two (or three..) isn't filling on the first jolt, but limbers up by the second, and now third attempts. I suppose a simple way to test that idea further, is does it still take two/three attempts to turn on if you've just shut down a moment before?

^ I agree, sounds like tired caps. Try the test proposed above, and check visually for bulged/oozing caps in mobo and PSU.

damn my main pc is doing this 😢 not an old psu either

I'll double check if it does the same thing after running for a while tonight. Sounds about right though as it gets used less now so explains why it takes a 3rd jolt to fully power up. The thing is hard to move so may have to wait till I can physically check it out.
Kinda glad its something easy to replace like caps, If were talking about replacing whole boards I have to start asking myself is it worth it? Only thing is I'll need to dust off my soldering skills which were pretty terrible to start with anyway.

Thanks guys