So you're saying it's somehow impossible to deploy QoS management in your network to limit IPFS the same way you would limit anything else?

Presumably one could also run IPFS (or Brave) in its own VM, container, or hardware server and to rate limit traffic in and out of it.

IPFS content loads slow enough without rate limiting

rate-limiting will only make the matters worse and again turn IPFS nearly useless

they haven't managed to solve these issues for 6 years now

Am I understanding this correctly?

1. IPFS's bandwidth is so low that it is unusable.

2. IPFS's bandwidth usage is so high that it makes the network unusable.

Yes, that has roughly been my experience. The application throughput offered by IPFS is quite low while the packet throughput is very high. I was experiencing 5-15% packet loss over my internet connection while running IPFS. I'm not sure if a bandwidth limit would even help or if it is related to number of connections.