It starts off strong: "Upgrade your software, not your computer". This is a great slogan that says exactly the right thing.
That said, I do not think the message should start off with such heavy fear-mongering. "Your computer is toast" is too much. A lot of people are going to immediately discount everything you say after that as biased and untrustworthy. Too much, too soon in the pitch.
Simply start off by saying that Windows 10 EOL is coming October 14. Simple. Factual. Accurate. Potentially educational. Ask " Did you know that a new computer running Windows 11 is not the only option? Installing KDE Plasma and Linux on your current computer may be a better choice." Honestly, it should be about as long as I have written here and then get into the benefits.
The emphasis should be on selling Plasma and Linux, not on bashing Windows. That said, the "what you will miss" section does raise good points that should be much earlier in the pitch. Switching means "no ads", "no registrations", "no subscriptions", more control over updates and app choices, less spyware, and fewer viruses. Again, you do not have to directly slam Windows, just emphasize that these are benefits that Linux / Plasma user enjoy. I would not say "what you will miss". I would say "what will you get".
I think it is not only ok but important to be honest that switching will take some effort. Highlight that, no matter what you use your computer for, there are apps available for KDE and Linux to do what you need. In many cases, they are the same apps you use already. However, it will also be common that the Windows apps you use today are not available and you will need to use something new. You do not have to hide from that. But do not make it sound so scary or even inevitable. The last person that I switched to Linux used Thunderbird and Firefox as their two most used applications. Most of the rest of what they did (other than printing) is web based. For them, the switch was not about using new applications at all. A better approach may be a sister site asking what software they use now and identifying alternatives so they can self-assess how difficult a transition might be. If this is done, it should be a in a resources or next steps section at the end. Do not link them away from the pitch.
Absolutely say that many Windows games run on Linux via SteamOS and Proton. Gamers are a big demographic.
It is at this point in the presentation that I would emphasize more strongly that staying on Windows 10 is not really viable longer term. People will have to switch, even if it is to Windows 11. Do you you want to switch your operating system or your computer? Get back to that excellent tagline. I think this question hits harder after you have done some convincing that KDE / Linux might work for them. There are benefits to moving to Linux. You cannot avoid the pain of leaving Windows 10. If you are going to go through a disruption, now is the time to try an alternative. And with that thought, really drive home that the economic side of the equation. On Linux, nobody will force you to pay for software unless you want to. On Linux, nobody will force you to buy a new computer unless you want to. Time to say no to Microsoft and take control of your computer. You cannot send this strong message until you have made people "feel" why they would want to.
The "for the technically minded" should be near the end. I think it is fine to mention it. Perhaps the spin should be that you will never outgrow Linux as even very technical users will find all they need. In fact, most of the technology industry and "the cloud" are driven by Linux already. It could be spun less as "Linux is really complicated" and more "those in the know have already made the switch". Then emphasize again that it is friendly enough for everyone. And then maybe finish off with direction on how to get started and where to get help.
Overall though, great to see the Linux community trying to take advantage of this opportunity. The message will reach some people. Even the Windows magazine article slamming the KDE initiative is marketing that will educate more Windows users that there even is another alternative. Great stuff.