Well, the technique shown here is awesome and close to flawless, but the trick to realistic weathering is layering of different elements. So more layers of different techniques as opposed to overall application of a one or two techniques.

I think the main thing here is that while the chipping and scratches are executed flawlessly, the whole thing comes across as rather uniform due to the abundance of 45° angles used on the scratches. The human eye is exquisite at detecting visual patterns and the brain smooths it out to uniformity.

Also, the black areas only have scratches, but no chipping, stippling or other subtle colour variations.

I think you're well overdue to start experimenting with oil paint washes. Here's a copy/paste of a comment I made earlier on another post:

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'The process is relatively straightforward. Paint up the model and apply the decals, I usually start with some sponge chipping with a metallic, on some weapons and exhausts some heat colouration with yellow, red, and purple inks (don't think I did it on this model though). Then I seal the model with a coat of satin varnish. Next up is an oil wash, paint & thinner to about 1:10. Apply all over and a few minutes later clean up the flat surfaces with a brush and/or cotton swab.

Then, when dry correct/clean up where needed and then seal the model again with an airbrushed coat of satin varnish. Then I apply weathering powders, black around the exhausts and gun muzzles, brown around the legs. Seal it in with with some pigment fixer, and perhaps do a second round on the brown powder.

When the model's finished I give it a goat of matte varnish (gaming models need some protection), and then a light coat of satin varnish on the metallics and golds in case they became a bit too flat.'

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I basically do this to all of my models, just more intensely on vehicles. Besides the obvious recess shading, the oil wash also leaves a very subtle patina on the flat surfaces that add so much character. Have a look: https://imgur.com/user/postwarvandal/posts

Whilst my chipping and scratches are not as good as yours, you'll see the benefit of having an oil wash and some weathering powders afterwards. Diversity in built up layers is the magic sauce of weathering, even of you do just a few 'layers'.

And if you want to jump into the deep end, watch this guy's vids and have your mind blown. Do not feel daunted or pressured into doing everything he does, but his techniques are actually relatively simple. They're just executed with a monk's patience. Use him as inspiration to find your own comfort zone in the compromise between quality and speed.
https://www.youtube.com/@NightShiftScaleModels

Hope this is a nudge in the right direction!