@laforea I think Razers are excellent laptops, not perfect but definitely worth their status as a premium product. But the Stealth models with a dedicated graphics card start at $1,600, and that's for a significantly slower card than the MSI. So it's not overkill at all, it's paying extra for a smaller laptop.
https://www.razer.com/gaming-laptops/Razer-Blade-Stealth-13/RZ09-03102E02-R3U1
You could save a little by getting a used model, but that's a risk, even if it's refurbished by Amazon Warehouse.
https://www.amazon.com/Razer-Stealth-Ultrabook-Gaming-Laptop/dp/B07X4BLSR8
The 15" models are similarly expensive, although at that price point, you'd get a 1660 ti. Or you could save some money and get an older model from a third-party seller, but that's a risk as well.
https://www.newegg.com/black-razer-blade-15-gaming-entertainment/p/2WC-001W-000U4
And yes, a 2013 MacBook Air would have a lot of trouble running Sims 4, mostly because of the integrated graphics chip, and probably partly because of weaker cooling. (When hardware starts to overheat, it throttles performance to protect itself.) Even the current Airs don't run Sims 4 all that well, although they'd do better than yours.
For the MSI, or even the Razer, I'm not sure you can expect it to work well for anywhere near ten years. You might get lucky, but laptops don't typically last that long. Many of them fall apart mechanically, or some component breaks, often but not always because of the laptop contstantly getting bumped as it's moved around. Even without that though, technology is improving enough that there's probably no computer out there that will still be fast enough for what you'd want to be doing in eight or nine years.
If you're still playing Sims 4, that's one thing, but there will probably be a Sims 5, or a competitor, and meanwhile regular apps will keep getting more demanding as hardware improves. The reason computers "slow down" as they age is not so much that their components slow as they age, it's that everything else is so much faster, and uses more RAM, which also runs at higher speeds. For example, a good computer in 2010 might have come with 4 GB of 1066 or 1333 MHz RAM, and now the standard is 8 or (much better) 16 GB at 2666 MHz or higher. Processors and graphics cards have improved even more. Obsolescence is unavoidable.
Having said that, the MSI or one of the Razers should be very good at what you want it to do for quite a while. And you can upgrade the memory now or later: RAM is cheap and easy to install yourself, whenever you happen to decide you want more.