I actually agree that they have similar effects if consumed similarly. Avoiding the mass consumption of short-form, attention-grabbing content is a great choice when you notice a decline in your ability to focus. I’ve occasionally done the same thing in my life, sometimes even cutting internet usage more radically than that, and it always created strongly noticeable improvements (or rather noticeable returns to my more natural state of mind).

That being said, I still browse lemmy memes and think it’s somewhat different from similar media for several reasons (these are broad generalizations, of course there are exceptions):

• Memes are more honest as they’re mainly aimed at making you laugh, and you can easily verify yourself whether you found them funny or not. Short-form videos will often contain stories, advice, or information, the value or danger of which you cannot verify so easily.
• At least if you’re looking in the right communities, memes are from the community members itself, not some slop by some influencer trying to get clicks at any price.
• I can browse through top of the day of my lemmy meme communities in a relatively short amount of time, get some enjoyment out of it, and then just move on with my life. I don’t think there is an equivalent platform for short videos. They want to keep you scrolling endlessly.