50GB per DAY? You can get unlimited SIMs but I think they're a bit more than £10. And 5G coverage, unless you're in a big city is really nonexistent.
I live in Stafford which has a population of 60,000, so just a big town really, and my 5G phone on fast.com says that I can receive 200Mbit from my 1st floor windows. My existing fibre contract is up this April, so I will check 5G prices again then, but at the time of writing this, the Three web site said that I can get 200Mbit for £30/month with no upfront cost.
Same deal if you go 3 unlimited sim only via topcashback, it will cost you £10.50 a month on a one year contract.
You'll need to sort out you're own router.
The whole standard x.xx% above inflation is just crap. Why should they be allowed to just set it by some arbitrary percentage above inflation