![](https://lemmy.ml/pictrs/image/a64z2tlDDD.png)
Libretube would have replaced the youtube app for me if not for how slow their instances are for me. So far I did not see any crashes but the pages would sometimes not load and would require you to change instances. I think the cause may have been that the instances are hosted far away from me geographically and that my current internet connection has been having issues for non-mainstream websites.
I had times where the android Not Chrome would freeze on my phone. I turned off an extension that adds a panel for more buttons and the freezes disappeared. Idk if this will be relevant to your problem since it's your whole phone that froze but maybe you're using some problematic extensions or you may have had some settings that caused it.