Those blocks are rated for way more than people give them credit for, like 1000 lbs each or something close to that. So your uncle's bench holding him up is not a fluke at all, and he is not just lucky. The real issue is not the weight, it is the sideways force, because when the ground shifts or freezes those blocks can slide apart and dump your whole build over. For a raised planter base they work fine as long as you fill them with gravel and set them on packed ground so they don't move around. Just keep in mind the dirt in a planter gets way heavier than you expect once it rains, so watch the total load.

Why does it always take someone else pointing it out for us to see it? I had almost the same thing happen with a scallop dish, where I was throwing on microgreens and a little citrus curl just because I could. Stripped it down to scallops, brown butter, and one charred lemon half and it looked a hundred times better. Now I ask myself if each thing adds a taste or just fills a gap, and if it's the latter it's gone. Funny how less stuff on the plate made me feel like I was actually cooking instead of decorating.