Meh. I think you're underestimating it, but I'm probably overestimating it, too. I suppose it depends exactly how good Sticky Web ends up being. The bulk certainly means something if getting Sticky Web up without having the setter die is important, and although the power creep indeed limits its capabilities (especially in the higher tiers), I do believe it will be able to take on a select few Pokemon rather well, so it's not total dead weight outside of setting up hazards.
If it counts for anything, it seems to have a decent matchup with many Defog users. It might be able to use Infestation (if it learns it, it probably does) when they use Defog, forcing them to stay in while losing 1/8th of their HP every turn. It could even set up Sticky Web again if they switched out after Infestation ended, and it has Encore if they try to set up. Obviously there are a lot of variables to this, and I haven't put energy into damage calculations or anything, but it's an idea I felt was at least worth bringing up. It doesn't help that a lot of flying types learn Roost, either. I'm also unsure if the Defog users it doesn't lose will even be used, I'm too lazy to analyze it much right now.