It's fair to say that the launch of Grant Theft Auto: The Trilogy - The Definitive Edition has been problematic, and a relatively rare example of Rockstar Games (and developer of the remaster Grove Street Games) being hit with extensive criticism. The visual style, performance and bugs have all been areas that have underwhelmed, and the Switch version is arguably among the worst of the ports.
A week after its launch Rockstar apologised for the release and confirmed there'd be a roadmap of patches and updates to improve GTA Trilogy; the first update rolled out shortly after. It's only an initial (and likely rushed) patch, though, and the feeling is there's still a long way to go.
Digital Foundry was among the release's critics last week, focusing initially on GTA 3 and describing the Switch version as a "big mess". As you can see at the top of the page it's now shared an analysis of the other two titles in GTA Trilogy - Vice City and San Andreas. It has also clarified that while the work for the video was done on the launch build, it's checked the games post-patch and states that the criticisms of the report remain unchanged.
Note: most of this testing is conducted on the launch version of the game. However, we have tested out the patch and found that none of our observations, performance metrics or resolution tests have changed... and even the San Andreas rain effect (which was supposed to have been improved according to the patch notes) seems to be unchanged.
The first half of the video focuses on the art style and some technicalities of the remaster's visuals, shifting to performance in the latter half. The Switch version is addressed but, once again, it's a negative picture. Resolutions cited are undoubtedly low both in docked and portable modes, with performance issues as it struggles to maintain a steady 30fps. The port is ultimately considered the 'bottom tier' version, overall.
Even if the Switch version is to improve in the future it does look like it'll require a fair amount of work, and therefore time. If it's given much priority alongside PlayStation / Xbox / PC is another issue altogether.
For now it seems to remain a disappointment on Switch, it'll be interesting to see whether fixes in the coming weeks and months can turn it around.