This is true. Privacy will always be a an arms race. Even offchain methods, like LN, aren't fool-proof. Encrypted data can be actively recorded by adversaries and kept to break in the future. Practically speaking, as long as privacy tech keeps progressing and gives old blockchain data privacy for long enough spans, it doesn't really matter if it can be broken in distant futures as the users will be long gone and the relatively recent data will be on better privacy tech. The differences in scaling capabilities between Monero vs Bitcoin, or even Lightning, look the same from above when we're talking about 10s, 100s of millions or billions of users. None of them can get anywhere close to that. If Bitcoin, in it's greater popularity and userbase, has time to figure it out, then so does Monero even more so. There are solutions available *right now* that would easily scale both like MimbleWimble or DAGs. But that change is very unlikely to happen on Bitcoin...Monero on the other hand is more flexible with changes if/when need be. So it has that advantage.