From what I have seen Bitcoin is being used more as an investment than for buying stuff.

For a new asset to become a currency, it arguably needs to become a store of value first, especially when the adoption of such asset is a voluntary market emergent process from the bottom up, instead of top-down, like fiat. It follows that early stage monetization of Bitcoin has users mostly utilizing it as a store of value. But once Bitcoin grows as an asset and becomes a bigger part of a persons net value, then the use case for buying becomes current, especially along payment solutions evolving, like lightning network.

Both are fairly easy to track, so may not be so great for crooks.

Lightning network has better privacy contrast to onchain Bitcoin, and there are ideas and potential developments to make it more so.