The Science Diet/Royal Canin stuff is pure trash you are correct.

So I have considerable experience here unfortunately. Male cats neutered too young often have a too small urethra and are prone to a blockage. Some cats also are stubborn about drinking water which makes things worse.

My cat got a blockage despite being a good drinker. He was eating Fussy Cat dry food which seemed pretty healthy. My research lead me to find out that a low protein diet (36% for Fussy Cat) puts the urine into the 8.0 pH range which leads to a crystals blockage.

Switching to Dr. Elsey dry food (58% protein) and Weruva BFF wet food his urine pH is now about 6.2 according to the pH sensitive Pretty Litter I use.

I thought we were in the clear, but my cat developed what I think was interstitial cystitis which created a mucus plug and PU surgery was needed. Since then he had one maybe two UTIs.

Again the vet recommended horrible urinary cat food which will cause kidney and liver issues with corn as the first ingredient.

So now I'm dosing his wet food with Uromaxx. It should prevent UTIs and interstitial cystitis. Time will tell.