Choppy Audio/Video on Zoom/Go-To/Teams/etc

With the whole COVID-19 thing going on this year, our company has decided to basically cease all traveling in favor of telecommuting. We decided to go to Zoom first and then, due to our Microsoft licensing, ended up migrating everyone to Teams. When we had Zoom, I only had 21 users in North America (we operate in CA, MX, and US), but with Teams we have many more users with licenses, but not much more using them to schedule meetings. It's still generally the same people scheduling/attending meetings.

Lately I've put together the amount of complaints and it seems the users are having to call into the meetings with their cell or desk phones to get intelligible audio. And this issue worsens if people are using their cameras. Many users are still working from home and we notice a decrease in choppiness when no attendees are on site and using their home Internet. Thinking it was a bandwidth issue, we pulled our utilization report from the ISP and they confirmed we were indeed hitting our cap at times, so I doubled our bandwidth. I'm still waiting on a new utilization report to confirm if that was enough, but based on the low amount of times we were hitting our cap, I was hoping that would do it. We also had our wifi installer out on site to resurvey and test the access points and he found nothing of interest save that our switch connecting to the Internet is older and should be replaced. The switch was replaced, but we just haven't finished the migration and one of the few things still left on the old switch is that Internet connection as below:

Juniper stack >>>> fiber>>>Cisco core switch >>Ethernet>>>>Spectrum

All of the users, APs, and desk phones are in the Juniper stack, and have been for about a year. We're in the middle of removing that old Cisco switch this week, I tried to move the Internet over last night to the Juniper but there was a typo in the config so we have to try again tonight.

Assuming we get the Internet connected directly to the Juniper stack and we have Internet access this time, what else should I be looking for to solve this choppy audio/video? Should we start implementing QoS for 30-50 users on site with 200M fiber to the Internet?