Spoken like a true non-developer who has done zero research. 

No covenants to not promote mining centralization, in fact it's the opposite. Covenants could limit how miners spend their rewards, distributing them across multiple addresses or regions, preventing concentration of mining power and encouraging more decentralized mining pools

Liquid is not an L2, it is a sidechain. Lightning is an L2 and is only possible thanks to covenant like op codes such as CLTV + CSV which essentially allows a covenant between 2 parties allowing for a lightning channel to be created.

Plus covenants could help scale lighting even further with channel factories.

If you're going to comment about this stuff at least do some honest research first.