I simply need wide support. I made some websites for a client who receives many 1. older customers and 2. customers from all over the world. I was conscious of the possibility that these customers could have either ancient devices or some highly obscure foreign devices not reflected on caniuse.com.
Now, if your domain ends in .dev you can just assume that your users are up-to-date techies, but otherwise I avoid anything newer than flexbox (which is just so useful).
Now, if your domain ends in .dev you can just assume that your users are up-to-date techies, but otherwise I avoid anything newer than flexbox (which is just so useful).