I just got a quote from that company here for a 4G wireless router at home, it's 15 GBP per month, you have to sign up for a 2-year contract. That's about $20 US per month. Unfortunately I don't have 5G indoor coverage at my location so the 5G option is not available, a shame as that is much faster. The router they supply has a built-in ethernet switch. Probably (hopefully) the purpose-designed router has a bit better throughput and latency than using an old phone to do the same job. It's a ZTE router. For the UK that's not too bad a price, compared to the rest of the broadband market that runs around 30 GBP per month on average. They say you get around 35-40 mbps with 4G so its a bit slower, and it's shared bandwidth so it depends on how many other people are using it at the same time, so it can be slower at peak times. If it was 10 GPB/month I might be tempted to try it. It has one advantage though, you can take the router with you anywhere you go, so it makes moving house or going on holiday pretty easy, provided your're within range of a mast.
On the other hand... a couple of people I know in shanghai have got FREE 100 mbps home broadband, on all new fibre infrastructure, from china telecom. So the UK prices are definitely not cheap.