I have 900gb in my account and on my 500mbps connection it took forever to download, not because of my speed but because of theirs and it just 'connection failed' at 80% many many many times and asking to relogin. It should be illegal. Not supporting just wget -c (you can use it with a lot of trouble/hacks and it's not reliable which defeats the point) is just clearly done to annoy you into not doing it.

I had a similar issue downloading a large file from Google drive (125gb?) over the web.

I had to install the drive client on a Windows laptop and download it through that.