Skeptics have been raising questions like yours for decades. If you are truly interested in answers then it is only one or two google searches away. In short scientists have already factored those concerns into their analysis.
Oh I fully know they have a lot more data than 1991-2023 (as is this chart). But of course they have no way to factor beyond like 1900. They don’t have the data and it’s why the models are always off. It’s also why I’m asking for it. It’s obviously constructed data designed to reach a pre-determined conclusion. The 1960-1991 data and 1930-1960 data is available (though likely using different sensors, locations, etc to calculate temp)
Skeptics have been raising questions like yours for decades. If you are truly interested in answers then it is only one or two google searches away. In short scientists have already factored those concerns into their analysis.