Mobile Payments for your food truck

I'm based in the UK, so initially was looking for opinions from there but in reality any experience/opinions from different countries would be very useful.

I'm exploring creating a new business - that offers an eSIM/mobile connectivity specifically to allow for payments via Square, Sumup, Zettle etc. It wouldn't offer a data connection to anything else, the two key elements being:

1. It allows a connection to multiple different networks (i.e. not just O2 specifically as a UK example, but EE, O2, Vodafone and Three - or US specific not just Verizon, but AT&T, Tmobile etc). Meaning wherever you are you have the best chance of getting a good connection.

2. It's designed to be very affordable. UK prices looking at say £5 to £10/$5 to $10 a month etc.

Would this be something that you think you would gain real benefit from? Or actually you have a solution that works pretty well currently?