You can certainly vote 3rd party, which is what I do. I can't vote for a party that thinks the solution to "systemic racism" is to eliminate law enforcement.
Is everything a conspiracy - no. The main party platform planks sure are (QAnon, Stolen Election, Vax Conspiracies). There are neo-cons that believe Biden is somehow responsible for global inflation and supply chain issues. Even their planks that are based in reality are pretty extreme - like banning abortion with no exceptions, restricting access to contraceptives, not allowing IVF embroys to be disposed of, restricting ghey marriage and ***.
The GOP is no longer the party of the William F Buckley Jr, Mike Rosen or Art Laffer, etc. Now it's the party of Alex Jones, QAnon, Trump, Tucker Carlson and Marjorie Taylor Greene. Since Buckley's passing, the GOP has lacked an intellectual anchor. Limbaugh looked like he might assume that role, but instead Limbaugh started flirting the with extreme right more and most of the right wing "influencers" were solidly planted even further to Limbaugh's right.
It seems that as the DNC became more tolerant/friendly toward big biz, the GOP went looney tunes. Clearly, the neo-con base no longer cares about how "traditionally" conservative your are (ie less gov't, lower taxes, etc), they care if you believe the election was stolen, so a die hard conservative like Liz Cheney was shown the door and the GOP trotted out election denier after election denier after election denier. IMHO, you're about to see 2 years of Marjorie in Chargorie - that's the modern day GOP. I don't see how anybody with a functioning brain can vote GOP. Maybe that's why they keep losing elections, there are just enough people with functioning brains to defeat them rather than some vast conspiracy to steal elections.