Been using 4G in the northern suburbs of Glasgow with good luck (Openreach can't connect fibre to our rented house as the telegraph pole in the garden has a red "danger" marker on it).
Bought a TP-Link AC1200 (aka Archer MR600). Got an "unlimited" SIM from EE to use with it (they say that means upto 600GB/month, but they'll only care if you use more than that for more than a month). Have been using this setup for over 6 months now without any downtime. We have a heavy gamer user and two of us use it for work. Netflix/Prime work without any issues.
Right now, late Sunday afters, I'm getting 63.1Mbps down and 33.7Mbps up - that's with three people using it. The speed tends to go up as high as 120/62Mbps, but I've not seen download drop much below 50Mbps during busy times. We find it's usable as a full time connection (it was initially going to be a temporary solution, but we've just given up on Openreach/BT actually finishing the half job they started in July - we have a fibre connection in the house, it's just not connected to anything outside). Prior to this we lived in the Borders and regularly had 54Mbps down over copper lines, so we're used to the speed.
Before jumping into any contract with 5G or 4G, check CellMapper.net to see if you can determine the best side of the building to put the router. Checked downtown, it would appear that Edinburgh only has 1 confirmed 5G mast - seems very odd. But the location of your nearest 4G mast should help determine the closest.