scaling is not just about making the blocks bigger, that would be the easiest and least efficient solution. scaling is about increasing the efficiency so the same space could be used better. for example the new Schnorr signature proposal alongside Musig would use the same space but can shrink the transaction size by a lot, hence increasing "capacity" which you can refer to as scaling bitcoin.
Well since this is as good opportunity as any, the question is: When Schnorr?
What is holding back this proposal, what are the cons (if any?) for it to be delayed? Is it a security risk?
well since it is a new signature scheme with a new OP code that probably requires a new witness version, it takes a lot of time to implement it, test it, optimize it and test it some more before adding it as a part of bitcoin consensus. consensus related changes must take a lot of time because they are security critical.
then it requires a soft fork that would also take some time to get the network to get on board and accept it.
the specifications of the proposal can be found here:
https://github.com/sipa/bips/blob/bip-schnorr/bip-schnorr.mediawikialthough things are moving forward but i haven't seen any dates.