The point being is that the bean counters (in the form of the DfT) aren’t doing their job properly; the approach since Covid of focussing on making small operational savings that knacker reliability and usability (while ignoring other areas of cost such as the leasing side of the industry) is nakedly political/ideological. The reform bill itself is pointless because it will almost certainly never be passed.
But the "Runaway profits" of the leasing side of the industry, decried as £400m, represent about 2% of net government support to the industry (£20bn including HS2 last year). Even if you ignore HS2 it rises to only ~3.3%
Even if they could be entirely abolished, it would make no meaningful difference to the railway industry's overall financial position.
And they can't be abolished without spending
£20+bn £30+bn of capital on new rolling stock (or somewhat less on purchasing the existing stock but likely still well north of £15bn). 15,520 vehicles to replace, essentially all owned by leasing companies.
EDIT:
Added a more up to date cost for rail vehicles.