The biggest incumbents will be able to absorb that as a small percentage of costs, but medium- and small- competitors will have greater burdens (as a percent of effort).
So big tech may see lower margins due to increased costs, but will also see less pressure from new entrants who will face a huge penalty for crossing from upstart to gatekeeper, and who will have entire avenues of differentiation outlawed.
So my read is that DSA/DMA will increase the long tail of competition, which doesn’t matter to big tech, at the expense of reducing disruption. . . Which does matter.
So, short term reduction in profits, long term entrenchment and. . . Not so much barriers to entry, but barriers to disruption.
That’s my read. But of course it’s a very complex system and it will be interesting to see what actually happens.