I’ve had to replace wheel bearings just one time before, on my late 70’s VW Rabbit, both front wheel bearings needed a re-do at 80K. The symptom was the front wheels started to make a growling noise that got louder the faster I drove. It sort of sounded like when you drive on a paved road, but one the road crew is working on, where they’ve ground off the top surface to expose the aggregate, prior to laying a new top surface on. You know how driving on that sounds?
In my VW’s case that sound, over maybe 1500 miles, kept getting louder and louder until it became impossible to ignore. How many more miles I could have got, hard to say. Like you say, for my VW there wasn’t any noticeable play in the wheel, but I did hear a slight grinding noise when spinning it by hand, with the wheel jacked up. There indeed may have been some play by the time I finally got it fixed, but a repair shop did the job for me then and they didn’t mention whether there was play or not. They did say the bearings that came out were in pretty bad shape, definitely needed replacement.