We're talking about overall trends, not to mention EU-level rules like GDPR.

> Unfortunately, small companies when facing level playing field are also easier to be destroyed by bigger ones

That's not what a level playing field is. Large companies destroy small ones through regulations. The rules impose fixed costs, which the large company pays once and the small company pays once, but the large company has more money. Then large companies lobby for "uniformity", i.e. national/international rather than local rules, which helps only them because local businesses with local customers don't have to be concerned with foreign laws, but further harms the smaller businesses because the "uniform" rules are naturally more complicated since they end up just being the intersection of all the local rules that anybody wanted anywhere.

GDPR actually reduced complexity of rules you had to deal with, some of them imposed since 1998 if not earlier.

It's just that companies happily operated as if the rules didn't apply. Then GDPR changed one crucial bit of the equation by making fines for breaking the law actually be impactful (see also how NIS2 introducing personal financial responsibility for company boards started putting up a fire into them regarding security).

In my experience, the uniform rules are actually simpler than what came before often. Pre-unification you often had to deal with them anyway because otherwise you had smaller market... where the big corporation could easily just deal with the rules just as well as you.

A small company is not going to have considerable win from more rules to deal with, unless it's a subcontractor to a big corp (and that's a precarious situation often) or where it's going to deal with possibly ever-smaller niche.

But as you point out, those rules de facto weren't enforced, and there are lower compliance costs if compliance is optional. The former situation is very bad because it leaves innocent people following the de facto rules at the whims of government officials who can then use violations to punish them for unrelated behavior, so unenforced rules are unreasonable should not be allowed to remain on the books, but that doesn't mean they're the same as rules that are actually enforced.

> Pre-unification you often had to deal with them anyway because otherwise you had smaller market

But you have the smaller market anyway, if you're small.

Suppose you want to create a new credit processing network. You're tiny and just starting out, you don't have the scale of e.g. Visa, but if you can get some local merchants to accept your new card, then you might get some local customers to put it in their wallet. And there might be some states willing to make it easier for you to do something like that because they want a local financial services industry instead of all that money getting hoovered up out of their local economy and into the coffers of New York banks.

But then most of the rules for that are federal, and onerous. Some of them are even international treaties. So you can't gain a foothold by starting in a jurisdiction that makes it easy, because the uniform rules make it hard. And then Visa and Mastercard end up with a de facto duopoly.