I'm curious to know the answer in an honest/practically-speaking sense not ideologically.
IMO, the downside of this container/web-app solution is the memory size that all the SDKs would need and this would add up eventually. But I'm not sure this fact alone could win any hearts over that sweet ease-of-entry-to-development.
People were nagging about latency and bloat in webapps and Electron GUIs...yet here we are...even SpaceX's console is a chromium instance.