Had to return my pixel 4a under warranty
Did you, or did you return it as per your statutory rights under the Consumer Rights Act?
I know it sounds like I’m splitting hairs, but it’s a subtle but very important difference. You shouldn’t need be touching any warranty here. Did you buy it directly from Google?
Under the CRA the supplier – not the manufacturer – is legally obliged to repair or replace in order to resolve a fault. In the first six months any fault is assumed to be a manufacturing defect unless they can prove otherwise (eg, if you clearly broke it). If this repair / replacement fails or is otherwise unsatisfactory you can then go into refund territory.
Under warranty the manufacturer can do whatever the hell they’ve written into their warranty, including “nothing at all”, so long as they follow their own processes. Any warranty is in addition to your rights, not instead of them.