If you're not rapidly scaling it probably doesn't matter. But if you're still buying (and maybe even using) Haswell CPUs in 2023, you may be missing out in a big way.
A moderately large Haswell cluster is equivalent in power to a moderately powerful modern server.
No not buying new, just using what was bought years ago. It still works, it does the job. Is it the best performance per watt, clearly no but the budget for electricity and the budget for new capital expenses are two different things.
If you go on Google cloud and select an E2 instance type (atleast in `us-central1` where my company runs most of it's infra) you'll usually get Broadwell chips.