The only bad upsell they do is in the booking process. Are you sure you don't want a hire car?
...while other low-cost carriers try to distinguish themselves by not being quite as bad as Ryanair.
Now Wizzair is "mostly not an airline" for me, because they have all the negative traits I hinted above. E.g. they'll happily advertise flights they have no intention of flying, make refunds hard, are as misleading as they can be about pricing, make it impossible to checkin online a few hours before the flight so that you have to pay their high fees, etc.
I wouldn't want the Ryanair experience for long-haul flights; but for short 2-3h ones within Europe, they're fine, I'm always considering them. Not for the perceived cheapness, but for the "I expect them to actually fly AND be on time" part.
Generally I agree with your view that Ryanair is decent at what it does, but COVID refunds happened only after the regulator stepped in to threaten them over their original "no refunds" and then "refund in the form of a voucher, with a short expiry date on it" policies actually being unlawful, and even allowing for the scale of its operations it received more complaints to the UK CAA than anyone else about refund handling during COVID.
They have an entire theory of marketing based on people believing that "if it feels cheap, it is cheap", and so they deliberately build in a bunch of annoyances (scratchcards, arbitrary baggage restrictions, checkout hoop-jumping, endless PR about removing toilets or running standing-only flights) which serve to make their service seem as cheap and nasty as possible.
And it works: some people simply ignore the nasty aspects, others are willing to put up with them in order to get a bargain, and yet others actually take pride in wading through the crap - usually expressing it in "I beat the system" terms. And here we are talking about it on a barely-related thread - carrying their marketing message further!