It's great to get various ideas from others on this, but it would be easy to make the mistake of assuming that all of the ideas will be equally valid for you personally, in the specific conditions you find yourself in. Your overall backpacking "style" and expectations factor in, as does the type of rain conditions and overall climate.
For an example of that latter, a brief but intense rain shower is different from endless days of drizzle. Of course temperature makes a difference too; sometimes it's warm enough that I might want a pack cover but no rain jacket. Sometimes (and in some places) after rain stops it can be days with no rain but the vegetation never dries out, continually re-wetting you. That happens a lot in the Pacific NW. OTOH, we don't typically get gully washer type of rain, or an almost predictable daily afternoon thundershower. Hiking in the PNW, I would never consider washing my wool socks on the trail; they might never dry. Hiking in SoCal or New Mexico, I would happily wash them along the way.
Your metabolism is a factor; I think that some people can hike at a modest pace and generate minimal perspiration; not an option for me, so some approaches to clothing/layering are different depending on that.
Your physical condition and experience can factor in, as well as the related hiking "style" of those you're hiking with. For example, if you want or need to take extensive breaks, maybe you want to carry an overhead tarp to put up for such breaks. If you're strong, then you "just keep hiking", making even the mid-day meal limited so that you don't chill out while eating it.
Footwear too. For me, it's based somewhat on the type of trip. If it's a weekend trip, I think that goretex light hiking boots are a fine option. If it's much longer than that, I agree that non-waterproof (quick drying) trail runners are best (for me anyway) --- better to accept getting wet and then having a chance to dry out again. Specific locale can be a factor there too.
So, IMO a lot of "how to deal with rain" wisdom is situational, as well as (of course) based on a variety of personal preferences.