Regarding Trafalgar I will simply post again what I have already pointed out, according to Nate Cohn who I don't think distorts the data, Trafalgar was the 7th most accurate pollster in 2018, beating Marist and Quinnipiac. It had a 1.87% error on average in favour of the GOP. By contrast, Fox had a 3.05% error in favour of the democrats, Marist had a 4.43% error in favour of the democrats and Quinnipiac had a 2.75% error in favour of the democrats, so Trafalgar's bias was within the normal range.
twitter.com/GravisMarketing/status/1067057315327692805
Regarding the infamous Kemp +12 poll which was off 10.6%, I can find examples of such polling as well in other pollsters, Fox News was off 12.9% in the Indiana Senate race in 2018 but I don’t see people saying Fox can’t be trusted. NBC/Marist was off 9% in the Missouri senate race and I don’t see people saying we can’t trust it, I can find such examples in every pollster.
Your second point contracts your first--either they're a good pollster who sees things other's don't, or they're making the same mistakes everyone else is. And you're finding literally one example for each other pollster which again contradicts your point, given Trafalgar has only done well with a few specific states.
