The budget £1000 e-bikes from Decathlon and Halfords are ok if all you want is a basic e-bike, but they use cheaper components to keep the cost down. which is fine if you aren’t too demanding on them. For example, they use mechanical disk brakes instead of hydraulic because they are cheaper.
It depends upon your intended use. If you just want a simple e-bike to get from A to B they will do the job, but if you are looking for a bike to do something more extreme then they are a bit lacking.
You then have to weigh up the cost of upgrading components versus buying a higher specification bike in the first place.