The rule that turns a wet three days from miserable into merely damp: one set of clothes never gets wet, ever, under any circumstances.
Base layer, socks, and something warm, in a dry bag, and they do not come out until you are in the tent with the door shut. Not for a cold ten minutes at lunch. Not because you are shivering at a break. In the tent, or not at all.
The discipline is the hard part and it is the entire trick. People break it on day one at a cold lunch stop, and then have no dry clothes for three nights, which is where a wet trip becomes a bad one.
What goes with it:
Put the wet clothes back on in the morning. Genuinely horrible for ninety seconds and then irrelevant, because you warm up within ten minutes of walking. Everyone hates this and everyone does it.
Dry bag the sleeping bag properly, and treat that as non-negotiable in the same way.
On maintenance, since your jackets keep wetting out: wash and reproof them. The repellent finish degrades with dirt and body oils, and a jacket that beads for one hour is one that needs cleaning, not replacing. A wash with the right detergent and a reproofing treatment restores most of it and costs a fraction of a fourth jacket. Do that before you spend anything.