Neither of those scenarios are typical for 'casual users' of the 2020s: at work, most have Windows laptops issued to them that they can't install things onto anyway, and elsewhere they are liable to do most of their computing on a tablet or a phone. There's almost nothing an exe file could do for a casual user that couldn't be done in a browser or mobile app, and most of them understand what an operating system is and that, on some level, there are cross-compatibility issues between them that they may be able to resolve with a tool.
>Photoshop or whatever
No one who _needs_ Photoshop is a casual user.