Answering for myself, backups. My SO and I both WFH. We generate a lot of data, personally and professionally. Most of that backs up to a local server, which then backs up to two off-sites. That server also backs itself up (plex, etc.).

I have to schedule it all to run at night because it will saturate the network during the day otherwise.

I have 1Gb/40Mb @ $100 internet for reference.