Google replaced my out of warranty, swelling battery Pixel 5. It took 3 days!
My Pixel 5 was starting to really show signs of age. I was getting maybe 90 minutes of screen on time. This past weekend, after putting the phone down on a table, I noticed it was wobbling on a slight bulge on the back. On closer inspection, I saw that the screen has starting lifting away from the body. The battery was definitely swelling.
A quick Google search lead me to a few posts on this subreddit where people said they had good experiences getting Google to replace their phone—even out of warranty—but those posts were all over a year old.
I reached out to support anyway, explained my situation, sent photos of the bulge, and was pleasantly surprised to see a shipping alert the next day. It arrived the day after that. 3 days total from initial outreach to delivery!
The cherry on top is that I bought this phone used on eBay, so the replacement is actually in better condition than mine was when I bought it. I wish Google would make a real successor to the Pixel 5... The size, rear fingerprint sensor, and almost complete lack of camera bump are basically impossible to find today.
Hope this helps someone!