Is Intel's 4th generation too old in 2020?

Want to get me a laptop for about the next 5 years i should rather take the 4th or 6th generation save 300 euro now it's worth it in the long run

My tasks / wishes: Long surfing or Word / Excel etc. Some compilers and did processing unpack and package typical IT profile

It depends on there are processors from to…

a gen 10 cpu the low end is slower than an i7 the 1 gen…

In theory, a worse older CPU would also be enough for your application areas, but it is of course more fun if everything goes a little faster. I would not go with Win10 under 8GB RAM and SSD. SSDs hardly cost anything today. So I would definitely install an SSD.

Neither nor. Both are too old.

Both Intel generations are too vulnerable (security holes)

Would bet on Ryzen.

New notebooks are available from 300 euro.

So gen. 4 is then a long way back, 8. Should it still be so that it can accompany you for a few years. The AMD Ryzen are also worth a look, good package from price / performance as far as the integrated graphics are concerned (something goes wrong with the blue ones).

You won't be happy with that for the next 5 years. Compiling takes performance, depending on how much you do, you need more to achieve reasonable times. In addition, at some point, if not now, Windows 10 will not run as well anymore as they incorporate new technologies that are no longer supported by old CPUs. Websites and browsers are constantly adjusted, etc.

I'd rather put 150 euro more on it and get you a clever new laptop. I got one for my mother for 460 euro, that at least something would be better than what you have in mind now. For 600 euro you get a clever i5, SSD and 8GB RAM, which would definitely be the best choice.