Some states haven’t been swing states for a long time, too.
I don't see this as a "states not counting" problem as much as the issues that come up in national elections affect different populations in different ways.
If there was a national popular vote, there would still be people who feel disenfranchised because the candidates don't see their chosen issues as vital to their coalition.
That was a short-term artifact of political realignments starting in the 1930s (New Deal Coalition) and—before that one had fully stabilized—1960s (Civil Rights).
Those overlapping realignments settled down into s new relatively stable alignment by the late 1980s; before the realignments most states were much stronger one-party states than the solid-red or solid-blue states today, and sometimes the second state party, if it existed at all, wasn't even the other major national party (Minnesota's Democratic-Farmer-Labor Party is a remnant of that: prior to the New Deal coalition, which it became part of and eventually joined the Democratic Party, the party competing with the dominant Republican Party in Minnesota was the Farmer-Labor Party, which was not associated with the Democrats.)
To be fair, there were only four elections in the previous 70 years that resulted in a Democrat winning. I think that avoiding something that like in the future is probably worthwhile, which is a minor argument against the electoral college based on past results.
Suddenly swung in 1992, and has been seen as solid blue since—not really an example of swing states switching as a state rapidly moving from Republican lock to Democratic lock.
Don't see why it would be. Obviously a flip will flip all of a states electors if it did all or nothing assignment, as most do, but sudden flip from consistent red to consistent blue in Presidential elections isn't a product of that. Might be a product of winner take all elections at other levels (e.g., state house, with the majority flipping reshaping donor alignments in the state and leading major voices to switch sides) but that's not what happened in CA either; the legislature didn't flip from solid Red to solid Blue at a time that would be consistent with it being a driving factor for the Presidential shift.