Which motherboard + CPU to play?

Do not want to trigger a war between AMD and Intel Fanboys here.

But I would like to get a new motherboard + CPU soon.
What would you advise for?

Currently installed:

Motherboard: Gigabyte GA-H81M-D2V
CPU: Intel i7 4770 (no K)
GPU: Palit RTX 2070 (possibly upgrade to 2080ti this year)

Actually, I'm just gambling on the PC, except for watching YouTube, Twitch, Netflix and Prime. Otherwise, I do nothing there.
It does not have to be high-end or the best of the best.
Solid and future-proof would be nice.
Overclocking, etc. I will not, because I do not know it.

In fact, Intel is a little better in games, but at the same time so much more expensive that this advantage fizzles. Intel can take you, if the money does not matter, otherwise AMD is simply because of the price-performance ratio (but still very good performance) significantly better.

For gaming I would recommend a Ryzen 5 2600X with an Asrock B450M Pro4 motherboard. However, you also need new RAM, your DDR 3 is no longer compatible. Here you could take 2x8 GB G.Skill Aegis 3000 MHz.

With the Ryzen Master software you can activate "Precision Boost", so that the processor automatically overclocks itself (ie beyond the boost cycle), if the temperatures allow it and the situation requires it. Therefore, a decent cooler would be appropriate.

Do not buy 5 2600X, it is more expensive than the 2600er although you can overclock the 5 2600 exactly like that. What I mean by that, the surcharge is hardly worth it since you can finally get out of both the same performance (+ - 5%).

Personally, I would go for an i5 8600k or i5 8400 because they are extremely good for gambling and have 6 cores that also provide future security. If you are more of a budget gamer I would take a ryzen 5 2600 or even a ryzen 7 1700. He has 8 cores and is extremely cheap (170 euro) besides he has the newest platform at the Ram (DDR4).

The questioner explicitly said that he did not want to overclock himself, so the Factory Overclocked X model.

Instead of the 8400 rather a 2600.

The 8400 is better in gaming.

Your current processor is still relatively good. An AMD Ryzen 5 2600 with B450 motherboard and 8 GB of DDR4 RAM is the most reasonable. The upgrade does not cost too much, but brings you much more power.

If you overclock the 2600 moderately to the level of the 2600X they are almost the same.

At the original price of the 8400 and in proportion to the then price of the 2600 you could have bought both, today imo the 8400 is too expensive.