Those plants were either exposed to herbicide/weed killer drift from nearby spraying or from contaminated compost/manure/mulch, or they have a virus.

My personal feeling from looking at the growth patterns is that they have a virus, likely cucumber mosaic virus.

Either way, the plants are unlikely to be productive for you. If you can still replace them with store-bought plants, that's what I would do.

If that is a virus or fungi it is good at hiding.

Cucumber Mosaic Virus fact sheet with photos

If there's damage on other broadleaf plants in the area, then it's more likely to be herbicide. CMV and 2-4,d injury do look very much alike.

You may also find this helpful: Photos of CMV on different varieties and at different stages

We''re already seeing damage in our area from herbicide carryover. Herbicide damage of one kind or another is much more common than virus, at least hereabouts.

See https://extension.umd.edu/learn/gardener-alert-beware-herbicide-contaminated-compost-and-manure.

Also see this http://whatcom.wsu.edu/ag/aminopyralid/images.html#img9 - also note that you can do a simple bio-assay to determine if the herbicide is coming from the soil. Plant 6 or so rapidly germinating seeds, such as radishes, beans or peas.

If positive, the seedlings will be distorted from the beginning.

It's true that herbicide is much more common. But that very stark transition from perfectly normal leaves to very distorted leaves is a distinguishing feature of CMV. Also, the lack of epinasty with the affected stalks still growing very straight makes me think it's more likely to be CMV.

Is that a pepper plant at the very bottom left of the photo?

At any rate, it's true that herbicide is also a possibility, as I have said before. But as I said, either way, those plants are better replaced. They're unlikely to outgrow the herbicide damage to the extent that they'll be productive, and they're never going to outgrow a virus.

Dramatic transition from normal leaves to distorted can also result from 2,4-D drift. Or an added layer of contaminated organic mulch/compost.

Do a very simple bioassay in that same garden area:

1. use seeds of radish, peas, or beans.

2. Plant 6 or so adjacent to affected plant(s)

3. waster and wait for growth.

R1sult 1: If seedlings damaged from the beginning, it's herbicide-carryover in the added organic matter. If so, see the info (and links at the left side of that page) at http://whatcom.wsu.edu/ag/aminopyralid/images.html

or

Result 2: If the seedlings are fine, and continue to be fine, the problem is either virus or drift.