Yeah that’s true, the guys doing my bathroom atm have done in one week what I think would have taken me a month fitting it round other responsibilities.
Could check out studio Bark who I think have a pretty nicely designed system and a middle ground between DIY and full built for you - priced accordingly too
I know if you get a custom one made from an architect you’d be looking at twice as much for half the size.
Can’t be hard to build yourself though?