I do a lot of canoe tripping, where submerging gear and/or packs is a real possibility. Also, packs lay partially submerged in the canoe bilge water all day long, and get dripped on by paddles.
The absolute best anyone in my group has found for sleeping bags is the Sea to Summit eVent compression dry sacks. These will float if you throw them in a lake (we have tested!).
I have an older Kelty Coromell long 0° down semi-rec sleeping bag. It's a big bag, almost 4.5lbs despite being down. That fits in a size Large/20L eVent compression dry sack, along with a pillow, liner, beanie hat, and wool socks. I can cram a couple other small items in there, but I wouldn't want a smaller dry sack for this sleeping bag.
I also have a Sea to Summit Tk II long 18° down sleeping bag. I carry this one in a size Small/16L eVent compression dry sack, but this one is the thinner/lighter 30d silnylon material (cuts the weight almost by half). I keep the same pillow and silk liner in this too, but the bag is slightly too big and becomes ball-shaped when compressed. If I had it to do over, I would get the 14L/XS size instead.
Note that I don't put my sleeping pad in a compression/dry sack, as it doesn't matter if it gets wet.
For clothes, we've tried different things, but everyone in my group has gravitated to the same solution: "Spacesaver" brand travel roll-up compression storage bags:
https://www.amazon.com/Spacesaver-Premium-Compression-Storage-Suitcases/dp/B06WW4QNSS
I usually fold up a spare change of boxers, base layer top and bottom, 1-2 pairs of socks, and sometimes a synthetic T-shirt, put them in the bag, sit on it, and zip it closed. It makes a nice flat shape that's easy to slip into a backpack alongside your shelter and sleeping bag. The multi-pack I bought had mediums as the smallest size, but a size small would be more efficient for what I put in it.
We also use one of the Spacesaver bags to pack out the group's trash. It's sturdy enough to re-use, but you don't feel bad throwing it away if something nasty spills inside it.
I have a 35L Sea to Summit 70d lightweight dry sack (not compression) I use for hanging as a bear bag. I don't put anything in it when it's in my pack, and usually carry it rolled up in my pack. It has held up fine to the corners of Mountain House pouches, but I'm careful with it and don't overstuff it.
My cousin has 30L and 55L "Black Canyon" dry sacks from Seal Line. These are the heavy duty rubberized material. We use those as bear bags too, and you can be rough and careless with them. Both crammed full is almost enough space for food for a group of 9 for 4 nights. The 30L would cover 3 guys for 3-4 nights. The smaller one weighs a pound, almost 3x what my 35L bag weighs (the difference is about what a 2L aluminum pot weighs!).
Other than certain food/snack items in regular zip-top bags, I don't take any additional precautions to waterpoof my gear, and I don't expect my pack to keep water out.
One thing I did learn the hard way one year, is to put any dirty clothes you won't wear again back into something waterproof. That year, those soaked up water in my pack, and I carried that extra water weight around in the ran for several days. I know better now.
