Not sure if I get the point. Sure there are big economical nodes like those on exchanges with lots of liquidity and channels to other important nodes. There are also others like ACINQ, liquidity providers. Still decentralization in terms of Lightning for me means that I can run my node/ nodes and open channels to other.

If those big nodes you pointed out were able to block me from using lightning noncustodial way than this would be dead serious issue.