Legislation is created and negotiated behind the scenes usually by a small number of lead sponsors who then build a political coalition of support before the bill ever gets to a Committee hearing. Many(most?) committee hearings are perfunctory nonsense attended by just a handful of members and the vote count is an open secret beforehand.
I agree that Congress should explore online voting, but I don't know that the ultimate equilibrium would look that different than what we see today. The typical Member spends Monday to Thursday in DC, Thursday evening to Sunday + August recess + multiple weeklong recesses in district or on the road.
If online voting was adopted, smart Members would still strike a balance between spending time in DC building relationships with their colleagues (and raising money) and campaigning back in the district.