Oneweb's satellites are 'bent pipes', which means they don't decode/route the data. They act like a mirror just reflecting signals back.

That used to be a great design when satellites were expected to last 30 years, and the 'bent pipe' design meant data compression, encoding, error correction and modulation could be upgraded without changing the satellite hardware.

In today's world where satellites are lower, cheaper and only last ~5 years, it makes more sense for the satellite to be able to decode and route data, which gives it a significant capacity boost for the same power and spectrum usage (since you aren't amplifying and forwarding noise). Phased arrays with hundreds or thousands of beams also don't work well with the bent pipe architecture, since cross-talk between streams is hard to reduce.