For clients their unspoken answer is 'upgrade hardware and stop whining' or 'we have strategic direction to deliver uniform client experience across platforms' which would just mean write some JS/Electron crap.
I also expected the integration with Google Photos to be excellent since Photos is a major Google service, but in a terrible case of bad timing I just happened to attempt to use it when Google had a Drive -> Photos service outage.
Meanwhile Slack is happily sticking with their Electron app and wasting the resources of hundreds of users machines and who knows how much electricity in total.
Companies like Dropbox tend to make the bulk of their money by selling to other businesses, as well, which by definition is the set of customers who care more about volume and price than craftsmanship.
Pretend you're a Dropbox salesperson, and your job is to go to other companies to sell them on enterprise Dropbox. How many times do you think you're going to hear someone challenge you on what version of Python the Mac client uses? It just doesn't happen.
There's many small ("indie") companies that make great Mac software, and do it by being Mac-only. That means they'll never be huge, but it also means they're never going to have a second-rate Mac client.
It seems no one bothers anymore, no matter the size of the company.
Any native clients we have now were built years ago and now they are only maintained.
I think nowadays even Audacity would be an Electron app.
But I suppose you're right. Even true of Slack. It's totally a meme that Slack's electron client is horrendous and bloated, but it probably hasn't stopped their growth, so where's the incentive for them to improve it?
In what sense is an app native if it uses cross-platform GUI libraries? Ahead of time compilation alone doesn't make an app native in my view.
There are cases where a custom, bespoke application for each platform is warranted, but that is rare. It's a continuum between the custom, bespoke and a UI/color scheme completely custom to your app.