It's precisely what this thread is about - CMS, and most people here are saying that all NRP's are evil and should pay more. Raising maintenance across the board would be unfair.
There are plenty of fathers who'd like to spend more time caring for their children but are prevented by the RP.
If a mother does not want to split care 50-50 then she can normally choose not to. Courts etc may suggest that co-parenting is normally a good idea but they'll say it works best in low conflict situations so all the mother needs to do is create conflict - even if the conflict is only over the time split.
Or a mother can move away citing family / support reasons, the courts will normally not force a woman to stay somewhere that'll damage her and thus damage her children so they'll allow the move and it'd be an unusual set of circumstances where the children remained with the father instead of the mother.
Courts cost a huge amount of money, take years and will normally make the mother the RP.
Even if the father's keen to take 50% responsibility the mother will be able to argue she provided more childcare during her maternity leave.
The judge will say "yes you're an excellent father, yes the mother's exaggerated some things and mislead the court. The father should see the children on alternate weekends and wednesday nights." the Judge will then say some infuriating platitude about "it's not the number of nights or the number of hours it's quality time that counts". "Quality time ffs", any time with children can be quality time - helping with homework, taking them to the supermarket, ferrying them too and from clubs (seems to be the best time to get teenagers to talk is in the car).
Schools, local authorities, doctors, Cafcass and especially the CMS will then treat the NRP differently from the RP. (society is utterly biased against men when it comes to children anyway).
If you increase the CM across the board, as OP and most mums here would want, that will unfairly push many NRPs into poverty and also hurt their children. It'd end up with more situations where NRPs who'd like to be the primary carer are deprived of their children and then pushed into poverty to give money to the RP so the RP can spend the money on childcare which the NRP would love to be allowed to provide. Many NRPs have to provide bedrooms, clothes, food etc to their children and follow them around the country, but still have to pay several hundred a month to their ex because mum has the children 4 nights a month more. Saying an NRP should always meet 50% of all childcare costs is also an unreasonable blank cheque.
(yes OP alleges her ex is a scumbag who abandoned his children, but not all NRPs are)