The Republicans have 3 things the Democrats can't match. At least 3:
1. Primary voters. Republicans are very much more activist and radicalized than Democratic primary voters. The Dems tend to be fact-based and policy oriented while the Repubs tend to be "true believers" in one or several of the cultural issues that motivate this demographic, e.g. religion, racism, xenophobia, belief in "free market" myths, 2nd Amendment myths, and belief in the myth of "individual responsibility". Radicals among this group constitute a vanguard which defines the terms of the Republican internal narratives. If you don't talk the right way you can't play. Because of the way the primary or straw poll process filters candidates, only the most radicalized candidates proceed to candidacy. That leaves Republican voters with only those choices who truly believe in (or lie about!) these causes. It is this primary dynamic that makes Trump the king of that party - he is the king of liars and maintains his ascendancy due to his cynical pandering to those self-same radical primary voters. Close observation of Trump's actual statements and actions show that he doesn't actually believe the narratives himself. But his lying works because of the presence of sufficient numbers of true believers or cynical pandering candidates in the Republican population itself.
2. National political structure. The structure of 2 senators per state and the operation of the electoral college give (by design of our Founders) a distinct advantage to rural voters. They are essentially over-represented in the Senate and over-represented in Presidential elections. There is literally no chance that Democrats can get these things changed as they are built-in to our Republic so as to not be changeable. When this structure is combined with the 1000 year-long trend towards urbanization, the 400 year-long trend towards mass education and the natural human drive to seek out personal advantages we see fact-based and policy-based voters congregating in cities and urbanized States. Ergo the hollowing out of the States that make up the "Red" map and the under-representation of (preponderantly) Democratic voters in the "Blue" map. IMO, there is nothing anyone can do to change these trends, certainly in the short term. However doubling down on education for everyone and using technological means of extending "urbanization" into the hinterlands may ultimately reduce polarization between rural/urban populations, possibly rendering the Republican Party as a more fact-based, policy based organization.
3. Violence. The Democratic Party does not have a radicalized vanguard of "true believers" as we see in the Republican Party. The presence of these people in the Republican Party, and the primary processes that make them influential, also results in violent people within this vanguard finding their way into more influence than their (small) numbers would otherwise give them. Combined with cynical demagogues who amplify, justify and showcase violent narratives and actions, people who would otherwise be shunned and/or criminalized find themselves being mainstreamed, accepted, emulated. This is scary and it is not matched on the Democratic side. Our Founders' fear of factions arising, which largely drove the design of our republican form of government, has ironically resulted precisely in the rising of violent factions among the people.
In light of the above, it seems near miraculous that the current Administration and Congressional majorities were actually voted in during the 2020 elections. It also seems the Democrats are at extreme risk of losing the reins of government in the midterm elections, or certainly in 2024. The strategy for them must be to create more Democratic states, and win over hearts and minds by reaching people who can be pulled away from the too-obvious trends in the Republican Party. Unfortunately, it also seems that for the Democrats to win power under current political conditions almost surely means we will see more violence in politics and on the streets.