I never understand why Nexus don't just start their own little network, I know the upfront costs will be a bit more but over time it'll surely pay for itself.

Could easily work like.

Mon - Fri:
W1 Morning to early evening -> runs onto 11 at night
W3 Morning to early evening -> runs onto 19 at night
Then have some deckers / full singles around which run the likes of commuter services and school bus runs which should work together that then run the extra evening services such as the 41 and 42 and 59 and K2 etc inbetween.

Sat - Sun:
Metro Replacement + Unprofitable Services

Better than spending money on tendering and giving money to other people to run it as basic as they possibly can and also don't have to spend money on Metro Replacements every weekend.