Hmmmm... can you define a "poor connection"? The web used to work the "htmx"/hypermedia through all the dial-up years where things were REALLY slow. I see no reason it would not work now.
How many people will give a runaround before answering the question?
It's meant to run on a laptop. In an existing site that people will already be using. It's free software. If you wanna build a native client, too, be my guest. I might at some point.
Having said that, for a time-tracking application, personally I wouldn't be OK with the risk of a browser screw-up (e.g. site data deleted, malware hoses the browser) losing tracking data. But you do you.
Yeah, I mean Google Sheets is created by Google, who can afford to throw craptons of money and warm bodies at the specific problem of making sure their browser is an inescapable part of the life of every modern computer user, so they can sell ads.
You and I don't have the same constraints and resources as Google.