Seems to me trouble with 2M blocks isn't that each block is 2M which is still quite easy to download and process. The problem is exponentially increasing size of blockchain as new blocks keep getting added and added relentlessly, this will ramp the actual total size of block chain much quicker. Its about 75G just now which is not really small. (In fact even with 1M blocks this problem remains that the blockchain will eventually be too big to be decentralised, that blockchain is just going to keep growing).
So why there is this rush to increase block size anyway, are the blocks nearly full just now ? How do you know or measure how much block space is being used ? Is there a way to monitor that ?
The blocks are not always full but supposedly sometimes there is congestion when a lot of transactions take place, resulting in slower time until transactions paying the standard fee make it into the blockchain.
Personally I think bitcoin core has it under control.