Oh I'm sorry you're having wifi problems - it can be a nightmare. We actually had mifi here when we first moved here, because there was no broadband! It's a little router (there are big ones and some as small as a smartphone) that take a sim card which is data only so gives you mobile broadband via wifi. It worked very well but it was an expensive option for us, compared to regular broadband at the time. Not good for gamers as there is a higher "ping" rate with mobile broadband, but I assume that wouldn't bother you! Once we did get broadband available, we had plusnet for a while, until it started being unreliable, so then we switched to Vodafone broadband (not mobile - just general broadband). The speeds were no different but it was slightly more reliable and really quite inexpensive. I think we paid £20 a month for both phone line and broadband, haggled a bit and got the phone line to include all calls and all mobile calls. So basically we never paid more than £20 a month. Over the years it went up a bit and I think latterly was £26 a month,
However, where we are, broadband was STILL incredibly slow (being rural) - we only got about 3 or 4mb per second! Which was ok for us, it worked, but not for the teenager who liked to play games on computer. Eventually we switched to Starlink - which is brilliant but unfortunately really expensive! It works great for us (via satellite dish) and great speeds, but that's because we're rural - open skies. I don't think it would work as well in a city due to a) obstructions (tall buildings) and b) other people with Starlink using your bandwidth. However some people do use it in cities - on a very tall pole attached to the roof! But I wouldn't recommend it if you have alternatives as there are set up costs as well! Buying the dish, installing it etc.
Maybe have a local at Vodafone broadband though. Now it may have been a bit cheaper because we had vodafone for our mobiles as well - I'm not sure - or it may have been a standard price - but it was certainly the cheapest one I found.
The main downside with Mifi is, if your mobile broadband goes down you have no alternative. Whereas here, if our main broadband goes down, you can use your phone as a mobile broadband hotspot (similar to mifi but not quite as fast as a mifi router), but it works!
We had a relative who was living somewhere temporarily and didn't want broadband running in and they had an ipad that had a sim slot and just got a data sim for the ipad and used that as a mifi router basically! ie used the ipad as a hotspot.