Each House may determine the Rules of its Proceedings, punish its Members for disorderly Behaviour, and, with the Concurrence of two thirds, expel a Member.–Article I, Section 5 of The Constitution.
The Constitution is clear: each House makes its own rules. Rep. McCarthy’s challenge to the proxy voting rule was clearly frivolous, thus the Supreme Court has declined to hear it.
The proxy voting rule is needed during the pandemic, otherwise it would not have been reasonable. Members of Congress are intended to assemble and debate, not to name a proxy and leave town early.
Many who initially opposed the proxy voting rule found it convenient and made good use of it, so it may not be easily repealed. However, repeal would not be enough to restore the ideal of responsible debate and action by members of the House. It is rare now for members to listen while others speak. More often they stay in their offices until it is time to vote. Party-line voting shows that the need for legislation is overshadowed by party loyalty.
Members might better be required to be present when the House is in session. But since Members have a voice in the rules, such a rule change is unlikely.