I'm not saying that it is ok for everyone but my daughter was using Teams, Zoom, etc for her schooling and my wife was accessing her school SIMS from home and it all went smoothly.
It appeared to go smoothly to you, which is not the same thing as it going smoothly. Let me explain.
While everything looked fine to you, on any video call the person at the other end is going to see a blocky, stuttering, low resolution video. Meanwhile you think it is all good because the video you
see with a 14Mbps download speed could easily be full HD if the person at the other end has a decent VDSL or better connection.
So unless you are on top of the exchange with something approaching maximum sync speed (which is a very small percentage of ADSL2+ users and not you) then ADSL technology is unsuitable for video calling. Even they you are going to be stuck with at best an SD video stream and anything else using the connection at the same time will tank the video quality for the other person.
Anyone claiming ADSL technology is suitable for video calling is sadly uninformed and just looks to those that know better a bumbling idiot.