There are two separate changes coming for EU entry. Sadly, absolutely everyone, including the kinds of junior interns who write travel articles for news outlets, is getting them mixed up.
EES, the Entry-Exit System, is currently planned for September 2024. That will involve upgraded passport kiosks that also take your picture and your fingerprints (which you can "recycle" if you return to the EU within three years), and will also record your time spent in the Schengen area automatically. That way you can't accidentally "overstay" if you don't get an exit stamp for some reason, but also, you can't sneak in for more than your 90-in-180 days if the border guard is busy and doesn't add up all the time on your previous stamps. If you have entered the US at a large airport in the last 10 years you will probably have used a very similar self-service system.
ETIAS, the travel authorisation, is planned for May 2025. It will work very much like the US ESTA. Basically it's an electronic pre-registration of your passport, so that you don't have to wait for 10 seconds while the border guard waits for the computer to see if you are a wanted criminal. It will cost €7 and be valid for three years, or until you change your passport. Everyone with a UK passport needs one, but it's free for under-18s or over-70s. ETIAS is not a visa — in fact, it is only available to people whose passport entitles them to a visa waiver — but the junior interns at Shite Online will all call it a visa, so prepare to see confusing headlines.
You can be absolutely certain that the launch of both of these will be accompanied by massive fanfare in the UK media (Guardian: "Sigh, another consequence of Brexit"; Express: "Now crazy EU bureaucrats PUNISH hard-working Brit families with OUTRAGEOUS visa charges") and if you book any kind of ticket to travel to a European destination there will be large red pop-ups on the website and in half a dozen e-mails from the airline. And still there will be stories of people who "didn't know I needed it".
By the way, the UK is introducing its own equivalent of ETIAS, called UK-ETA. It is more expensive at £10 and only valid for two years. It is already live for one country (Qatar) and 6 more Middle Eastern countries will be added this month, as they very sensibly test it in small steps. It will eventually be rolled out to people from all UK-visa-exempt countries, and I guess might even be applied to EU citizens visiting the UK before ETIAS goes live. So if you hear people complaining about ETIAS, you can remind them that the UK does exactly the same.