I’ve been asking ETH devs, and it sounds like people prefer to use WETH though in their contracts though and use
msg.valuemostly just to wrap ETH into WETH.
This is true, but usability wise this is not great. Developers prefer to use WETH, because it makes their contracts simple - there is no special case for native currency, but everything can be coded as ERC-20 transfers (forgot about payable, etc.). However, the users prefer very much ETH, as WETH wrapping process still is not that simple. For example, wallets and user interfaces do not offer this option by default.
To make the matter more complicated, there are several versions of WETH. WETH10, being the latest, is very superior feature wise: transaction fess, relay support and such:
It is not widespread yet, though.