So we really love what the folks over at Glide have built, and we're not looking for a fight on "coolness" ;)
Overall, we're used in a different way: Stacker let you make systems for your team to work from, or portals for your customers to self serve. We can be backed by either Google Sheets or Airtable, and we work on desktop and mobile.
We've got a real focus on creating something for daily use, and that gives you really fine-grained control of your business rules and data security.
Glide is, as you say, just GSheets, and just mobile. If you check out their examples, you'll see they're more focussed on small utility apps (e.g. Attendance Tracker) than larger systems.