600Mbps vs. "Gig Speed"?

I recently had to down grade our home services due to Covid-19 buisness loss.  I had "Gig Speed" and reduced to 600Mpbs.  600Mbps should be well more than needed for a 3 person home, but seems to take a lot longer to access simple streaming items like vidoes on fb, Youtube etc. I have the latest modem, and the pods for X-fi.  Just still seems slow for the expense. Thinking to move to fiber and get dedicated service since 600Mbps seems like a true farce. Any resoltion other than different ISP?