I've used Teams in different places now and I'm coming to suspect the issue is less with Teams itself and more with upper management trying to cheap out on the infrastructure. A company I used to work for tried to cut down on their server expenses by minimizing the resources available to VMs. It meant Teams, made by the same company that makes an OS that gobbles both kinds of memory like it's trying to fatten up for winter, worked as well as a vehicle with a leaky fuel line, which is to say poorly and with occasional fires and explosions. Another company I worked for had every part of Teams working fluidly. Phones, workstations, events and calendars, even the stupid AI BS, all ticking over nicely. The difference really seemed like it was in the infrastructure. With enough resources, it just worked.