The leaf marring appears to be due to one or more factors - a pathogen (probably fungus, though some are bacteria) and perhaps some chewing from generalist plant-feeding insect like Flea Beetle. Given how early in the growing season it is and the appearance of the damage on old leaves (as new ones haven't emerged yet), this damage was done either last year or in prior years.

"Leaf spot" is the collective term used to lump most leaf-spotting infections together and, while they can cause substantial cosmetic damage, they don't usually impact the overall health of the plant too much unless infection is severe and causes repeated defoliation. As with many diseases, weather conditions from year to year influence how easily new infections spread and how severe or mild such infections become. Evergreen plants, since each individual leaf is retained for several years, unfortunately take awhile to cover-up or grow out of such damage, though each year in spring and/or autumn they will shed their oldest and sometimes most damaged leaves. Therefore, the easiest way to determine an infection is under control or subsiding is merely the absence of spotting on new growth, since it will take time for the older affected growth to disappear.
https://extension.umd.edu/resource/fungal-leaf-spots-shrubs

Determining whether the pathogen is fungal or bacterial can be difficult, and fungicide treatments rarely control bacteria. In either case, they are also only preventative, so timing of use needs to be precise in order to be effective; rain or windy weather during opportune spray times can render control attempts not very successful, for example. These are the reasons why we tend not to recommend spraying fungicide as a means of control. Instead, all you can do is to make sure the plants are in optimum growing conditions so they have the resources they need to best outgrow the damage and not contract any new infections. For azaleas of any type, this generally means excellent drainage but irrigation as needed in times of drought, afternoon shade (or at least dappled light during the hottest hours), and good air circulation (minimal crowding) so wet leaves dry relatively quickly. Using mulch (be it bark or living, like a groundcover) around the plants helps minimize any risk of fungal spore splash-up onto foliage in heavy rain; it also keeps roots cooler and damper in summer, when azaleas can be easily stressed by hot, dry weather.

Flea beetles are a very common insect that typically feeds on shrub foliage in mid- to late summer. They are not the only culprit which can chew holes in foliage, so without seeing them in action, this is only a guess. Here too, damage is mostly cosmetic from leaf-chewing insects and not harmful enough to warrant pesticide use. (Even so, the pest would need to be identified first so the right control could be chosen.) Chewing insects are a possible cause of the holes we see in foliage, but dead tissue from pathogen infection can also dry up and fall out of the leaf, looking like a chewed hole, so this is not a concrete determination.

The solidly-brown leaf edges may be simple winterburn, a condition that occurs in windy and/or cold weather where the loss of water from evergreen leaves is faster than what the plant can absorb from the soil, especially when the surface soil moisture is frozen. Nothing needs to be done about this after the fact, though checking on plants during dry and mild winter periods (and watering when needed) could help avoid future winterburn.

Miri