The answer is this: because you obviously live in a liberal echo chamber, you fail to understand the arguments of your opponents or their rationales for doing what it is that they do.

In this case, Republicans have never pushed for a constitutional amendment because they don't believe they need to; the Constitution does not cover abortion, so the time and expense of an amendment is meaningless for an issue which they believe currently belongs to and always historically did belong to the states. All that is required, then, is for the court that created the right in error to understand its error and reverse its decision, which now it looks like it has. That is exactly why a constitutional amendment is and was wholly unnecessary.

I mean your question can even be turned on Democrats: if they were that worried that Roe could ever potentially be overturned, then why didn't they, when they have the power, push for a constitutional amendment to enshrine it in the Constitution? They didn't because they believed they didn't need to; the right was already established in the Constitution according to the courts. A constitutional amendment in that case would have been superfluous. And now it looks like that's something they'll have to do in order to force abortion on states that don't want it.

Which, I believe, is a result of living in an echo chamber: if enough people around you say that abortion is a constitutional right and Roe was properly decided, you end your analysis there. And when, as now, the SC notes that Roe was wrongly decided and that the decision then and certainly now cannot pass constitutional muster, you all have a collective meltdown.