It's totally worth putting an SSD in a 2019 notebook. People have said it before, but I'll be straight with you: a mechanical hard drive physically moves to read data, so there's always that annoying lag. SSDs don't have moving parts, just electronic components, so they're absurdly faster. You'll notice the difference not just in Windows boot time (which goes from minutes to seconds), but especially when opening heavy programs, a browser with tons of tabs, everything just flows smoothly. And a 2019 notebook is still solid, still runs everything you need without issues.
Here's the real question: how much do you want to spend now versus how much you want to spend later. A 256GB SSD costs like 100-150 reais if you grab a Chinese brand, or about 200-250 if you want a more well-known brand. That's dirt cheap compared to buying a new notebook, which runs like a thousand reais or more. Your PC will easily last several more years with that swap.
Here's a detail nobody mentions: after you install the SSD, don't migrate everything from the old hard drive at once. Keep the mechanical hard drive in there, just move Windows and the programs you use every day to the SSD, and use the hard drive as storage for files you don't access all the time. That way you don't run out of space (256GB fills up fast if you dump everything in) and you still get use out of the capacity you already have. You can even pull the DVD drive out of the notebook and put in an adapter to fit another drive in there if you need more space later.