I maintain a ~250K LoC Zig compiler code base [0]. We've been through several breaking Zig releases (although the code base was much smaller for most of that time; Writergate is the main one we've had to deal with since the code base crossed the 100K LoC mark).

The language and stdlib changing hasn't been a major pain point in at least a year or two. There was some upgrade a couple of years ago that took us awhile to land (I think it might have been 0.12 -> 0.13 but I could be misremembering the exact version) but it's been smooth sailing for a long time now.

These days I'd put breaking releases in the "minor nuisance" category, and when people ask what I've liked and disliked about using Zig I rarely even remember to bring it up.

[0]: https://github.com/roc-lang/roc