I agree that Trump's move was very bad, but we know that Biden didn't need a new law to "fix" the situation at the border. After Trump blocked that law, Biden made the executive order that for years he claimed he couldn't make, and then the situation at the border got "better". If Biden had instead made that executive order in, say, Fall 2022, there's a good chance that the situation at the border would not have been as salient in 2024 and Trump wouldn't have been elected. (Or, if Trump was still elected, he wouldn't have a mandate to come down so hard on immigration like he's doing now).
The reason Biden didn't make the executive order earlier is because of pressure from groups like the ACLU. The ACLU was simultaneously telling us that Trump is a threat but also pressuring the administration to keep pursuing policies that were clearly playing right into Trump's reelection campaign.
By the way, the ACLU was also against the border bill that Trump blocked.