That would be solving the wrong problem. Unused bandwidth is wasted bandwidth, you are paying for resources you can’t use. Limiting bandwidth is counterproductive and will be somewhat helping as a side effect.
You shall be able to saturate upstream all the time and still have low latency for all other applications.
Since this is evidently not the case for you — your network likely suffers from bufferbloat: https://www.bufferbloat.net
Run this to confirm (ideally, using wired connection, not wireless, otherwise you might be conflating wifi specific issues): https://www.waveform.com/tools/bufferbloat
Once confirmed, enable SQM on your router (it goes by a variety of marketing names) to completely fix this and related issues once and for all. In fact, your browsing experience will likely improve too.
If your router does not support SQM — defenestrate it, and get one that does.