Cat food - Purina Proplan

[Seaair2]

We got our cat from Cats Protection 15 months ago, he was eating purina proplan dry food there and until now I’ve kept him on the same, apart from moving him from the kitten to the adult range. At one point I did try and switch him to Wainwright’s, which he ate but it seemed to make his poo a little runny.
Is purina an ok food?
Ranges like James Wellbeloved are meant to be healthier aren’t they?

Its not the worst but not the best either.
Mine have thrive dry and encore dry food

My last cat was pretty much grain free until near the end when he needed a gastro diet. I'd expected to switch my new rescue to grain free, but like your cat, OP, she came to me on Purina (One not Pro-Plan) and as she's thriving on it (perfect non-smelly poo is a big win!) I'm keeping her on it. She won't eat wet food beyond a taste so she has a second bowl with different dry food to add some variety, so far she's had Lily's Kitchen and Krave, but she much prefers Purina.

It’s just tricky to know if I should keep him on purina or try and switch! I don’t want to be feeding him something that long term isn’t healthy, he’s one and a half years old at the min.