@santiago
I have an old ThinkPad T43 from about the same era (early to mid 2000s) and I can use Matrix chats, I can read emails, I can browse Gemini and even the Web (without all the fluff, using w3m), listen to music and watch videos at 720p and even low-complexity 1080p ones, I can code using vim, it even runs Quake3 more or less well…
Just start Firefox, open 4-5 tabs of "modern" web — and the machine becomes unusable 😂