A good question.

Yes, I would say Avalanche is also very interesting. I think NEAR, Tezos and Cardano are also very interesting.

Researching for such an article is very time-consuming and giving an overview over more technologies would basically mean reducing the depth of inspection. So I decided to stick to 3 techs here.

Why not Avalanche?

The consensus of Avalanche is very interesting, but the consensus whitepaper does not even mention interoperability. The platform whitepaper does it:

"Interoperable and Flexible Avalanche is designed to be a universal and flexible infrastructure for a multitude of blockchains/assets, where the base $AVAX is used for security and as a unit of account for exchange. The system is intended to support, in a value-neutral fashion, many blockchains to be built on top. The platform is designed from the ground up to make it easy to port existing blockchains onto it, to import balances, to support multiple scripting languages and virtual machines, and to meaningfully support multiple deployment scenarios."

It was very hard for me to find out how Avalanche actually tackles interoperability or better let's say not possible. Avalanche is quite new and I guess there will be more info in the future.

NEAR is very interesting because it might be one of the first blockchains going online with sharding.

Tezos and Cardano did not make the list for the same reason: They are not that advanced, though their goals are ambitious enough. Cardano is currently about to deploy smart contracts support, so it might be comparable to Ethereum 1.0 but with a PoS boost (giving a lot more tx/s). However to become blockchain 3.0 there is more necessary (their roadmap calls this basho and voltaire upgrades, giving scaling and governance). Taking into account how long Cardano took to get to smart contract support, I guess it will take many years until next progress will be seen. Tezos has smart contracts and governance, so it would rather make the list, but I don't see a clear approach to interoperability.

Edit: I forgot one thing: What I also don't like about Cardano is that it has no slashing, there the penalties work by denying rewards. I think this is a bad design decision if you want to have interoperability with things like bridges/peg-zones.