Everything should be quicker; I mean from loading the game to responses from customer-support must be quicker. We are all at gambling sites to find entertainment and making us waiting for more than expected/usual time must be annoying for any gambler. I support fun-seeking gambling still customer support is more important when gambling sites are dealing with actual hard-earned money.
Sadly depending on the chain, the betting can be pretty slow if it's not centralized. At least in the sites i've played on. Luckily it doesn't affect anything else being slow.
you forgot that the speed of the pages will also depend on your connection because its useless if the site is centralize and known to be fast but if your connection is capped or lower than 4g . also not all decentalized sites are slow . ive been using some dex sites on the past and my connection is only average (3.5g) but the site loads okay . costumer support on the other hand is not my main concern because i dont experience any issues when playing a gambling online .
When you do stick into a reputable gambling site then you wont experience too much when it comes to problem unlike on playing into new and shady ones.When it comes to loading times it do only matter with internet connection or into sites ui itself would have the problem.
What matter most to me is fairness,security and fast support.