Which preset is this? That’s a clean image right there.
Just playing with parameters, I saved it locally here.
I think it looks clean because It’s a light slotmask obtained with cells height being 1/3 the height of the scanline.
For that reason, It works good for 240p content, but not so well when resolution increases.
Also, Hyllian’s ddt-xbr-lvl1 is used to 2x upscale.
Zoom out until any artifacts disappear. I use a very bright screen. If these appear dark for you, you can try brightening your display.
CyberLab Megatron NX W420M 4K SDR Game Video Composite Shadow Mask Smooth Advanced.slangp
CyberLab Megatron miniLED W420M 4K SDR Game Video Composite Shadow Mask Smooth Ultra Advanced.slangp
On the dark side again.
This is going to replace Monitor-for_HigherNits.slangp preset. It is quite basic, no halo, no bloom; just scanline morphing and mask set to 80%.
It performs really well in a dark environment even with a modest 250cd panel set to the max.
New toys!!
These are some new presets I made using the brand new Uborder shader by @Hyllian featuring the NTSC Section from CRT-Guest-Advanced-NTSC.
Special thanks to @Hyllian, @guest.r and all the other shader devs, artists and other contributors who made this possible!
I don’t recall having scanlines back in the 80s-90s, nor do I remember seing pixels or sharp edges, yet the games always looked clear 
Oh no no, you miss the point! 
I don’t want to start a war here, to each his own. We just couldn’t afford good tvs bigger than 17", couple that with an RF or s-video connection at best and you simply had a whole different experience.
Like you said, it doesn’t mean they are not there, is just that for the life of me I really can’t see them.
Since when having a different perspective or opinion means there’s a threat of war? Speak your mind and speak freely.
There’s nothing wrong with discussion and not all discussion leads to debate.
Also, I don’t think I missed the point at all as I’m aware of all the factors which you mentioned, I just added some additional perspective due to the statement taken at face value.
In my example you had to zoom in to see the scanlines clearly. So it’s not hard to understand why you would make the statement that you did.
Nobody knew what scanlines were back then anyway, and then emulators came along which gave you them but no masks.
Thankfully, we have sophisticated shaders now and know a lot more about proper TV adjustments. 
If e.g. contrast is set too high on a TV, or if it’s out of focus you can basically have “mask-only” look. It’s also just natural on very small sets.
Here’s something from my 21" (about 20" viewable) set pre- and after adjustment.
Even on small 14" with PAL 50Hz output you can see it’s still different from plain “mask-only” look.
