I have a crappy ADSL ISP, which is supposed to deliver 8 Mbits/s, but can painfully reach 3Mbits/s when everything is ok, sun is shining, weather is sweet and moon is aligned with Venus and Saturn.
I connect with wifi to the modem, but I also tried with ethernet, and no change.
Also, there is no difference if I connect with my desktop or my laptop.
And the ThinkPad wifi stuff is pretty good, pretty reliable, real pro stuff.
If I connect with my smartphone 4G, I can get a 30 MBits/s minimum, and no ping troubles.
So it's clearly not a computer-side issues.
Problem is I live in a very small town (about 1000 persons), and only have the choice between two ISPs, and they are equally bad alternatives.
My modem is provided by my ISP, so I don't have the choice, I cannot choose my modem.
I have a good Cisco modem/router, which worked perfectly in my old house.
But I can't use it here, I tried and no way, it's just impossible to use anything else than the ISP provided router

And thanks to my wonderful ISP, and its hardware limitations, I cannot even plug my Cisco to the provided router, while it was possible in my old house.
So I can't even set a LAN in my house
And of course, I need to frequently restart the modem, about every 3 days, if I want a minimum transfer rate. Would not be fun enough if not.
This is why I use my 4G smartphone to connect most of the time.
But I downloaded too much games this month on Steam, my 4G package is gone until 17-07-2020...