Coverage map a work of fiction?

[notdodgy]

In several local places I go to regularly the coverage map says good 4G coverage inside and out.

In practice it is unusable - there are are several bars of signal but no or intermittent bandwidth. 
5G exists near my home but in main shopping areas - where people are - no coverage.  

I just moved from Three and coverage was great.
I signed up for a virgin media package and the £25 for the phone part includes unlimited data - that is pointless if you get no signal or no bandwidth.   

I think if O2 cannot provide the bandwidth the cost should come down.

[Enlli]

Coverage maps are computer generated and don't take in local conditions like trees, tall buildings etc.

They also don't take into consideration data capacity, just signal strength for making calls.

I always recommend trying PAYG SIMs on different networks to find the best network for you.

Here O2 and Vodafone are the best, EE is weak and 3 none existent despite saying excellent coverage.