From a business standpoint I've noticed these two mindsets prevail:

With paid SaaS, there's always somebody to blame for missing features or outages. From my POV either way the IT department is getting blamed if a system goes down, and the overconfidence in the vendor to fix all issues timely is not always realistic.

Business leaders have conditioned themselves to being sold something. With open source they still expect a CEO or some figurehead to give a presentation on how the free tool will benefit the company, even though it doesn't make sense when there's no incentive to sell.

On the flip side, open source expects users to accept bad and outdated UI. The people who need a more simplified UI aren't the people who can make the changes.

1. People install communication apps because someone they want to communicate asks/tells them to. I don't want to use Slack, but people who pay my bills use Slack, so I use Slack. I use Matrix too because I believe in it philosophically, but the UX is a little rough and very few conversations I want to have are actually taking place there.
2. I don't really understand this one. Adblockers are relatively easy to install and the modern web sucks without them.
3. I haven't encountered much of this in a long time, but familiar feels safe to people. Something they haven't heard of might feel sketchy.
4. This sounds like someone trying to persuade you to install an app because you using it would be convenient for them.

Libre Office will break their computer and lose their emails.

Few buttons in a different place and they no longer instantly know how to use it == broken.

People stagnate and tech savvy people don't realise how tech savvy they are.

For a lot of people free equals inferior /bad.

You've explained the mentality - people don't particularly care to know.

Why would people put in the effort to solve a problem they're barely aware of, and don't understand - particularly if putting the effort in to understand and address won't even solve that problem? If you want to add problems to people's lives, you need to tone it all the way down.

Don't get me wrong though - you're fighting the good fight - and meeting people where they're at helps, so I guess this is a decent place to start.

Most people are just not technically minded or have the patience to figure stuff out on their own. All most people understand is "buy thing, it works, I go on internet and play games" ... then after a year or two their laptop, phone or device starts to run slow because they never maintained it ... "thing slow, thing no good, throw away, buy new thing" ... then start again.

I have several intelligent, highly educated, professional friends who have bought expensive phones and laptops, never maintain them, complain about them, dump them and buy new ones within a year or two. Literally buying $1,000 phones every year or second year.

Meanwhile I bought a galaxy S20FE a couple of years ago. I got it on special with my phone company and paid $100 for it over two years. I added it to my collection of just about every phone I've ever owned over the past 15 years, that are all still working, along with laptops I've upgraded to Linux and tablets I'm experimenting with.

yeah i have a friend, they only play the same 3 games, web browse, and talk to a like 2 people on discord. they could easily move over to linux/matrix and never notice the difference, i have offered to help them several times, but they just dont wanna do something different. they know how their computer works already, why change it? i argue that there really isnt much of a change, but its enough to completely dissuade them.

I couldn’t say why some are so fully propagandized into servile corporate bootlickery. But enough about r/neoliberal[1][2].

That open source makes it any less susceptible to privacy and security concerns.