No idea if a thread like this is in scope of the discussion forum or not. Just answering since I was pinged, apologies to mods if this isn't suitable. I'm also probably not the only forensics analyst on this site, so don't rely on my words too much.
This is a question that cannot be answered properly, nor is something anyone on this forum can say with complete confidence. Cellebrite Premium is strictly for law enforcement, I've never used it. When it comes to products like that you can only speculate or make decisions based on your judgement because the details of the products are intentionally withheld from the public. While this is not a great answer for you, it is the best you can be given that doesn't involve someone making guesses or answers based on their informed knowledge, which may or may not be reliable.
Pixel devices have had attacks mentioned in news media before: https://nos.nl/artikel/2486578-nfi-weet-honderden-cryptotelefoons-te-kraken-een-bankkluis-in-een-bankkluis (article is in Dutch) but you aren't made sure of the details, the article says 'crack' but is that just news speak? Is it just a standard extraction? What Pixel was it? Did the suspect slip up? Just an example of many details left unanswered.
Mobile forensics tools advertise the same way, Cellebrite usually avert talking about their capabilities with Google Pixel devices in comparison to iPhones, but GrayKey/VeraKey claim they can extract Pixels up to the Pixel 6 series on their website. Are they hiding details? Is it out of date? Why not the Pixel 7? What type of extraction is it? You don't really know, so you could assume their capabilities are either less or more than what they say. As for the Galaxy, Cellebrite and GrayKey claim they can for both. I would be more alert of Samsung devices. Overall I would imagine they have a difficulty with Pixels as they would put less attention to it in comparison to Samsung or OnePlus, the security posture of Pixels compared to other devices, and the use of OS' like GrapheneOS. But, I will never say never and say it's definitely not impossible to unlikely.
If digital forensics is part of your threat model then your usage habits need to be changed, this is not something any amount of special hardware or software can fix unless it was designed to be entirely anti-forensic. Physical exploitation is practically impossible to protect against unless the phone had a bomb strapped to it (and even then, you have teams to defuse bombs!). If your device is secure and not extractable, that doesn't mean it will be once it has been seized and left in their hands for a couple of years, waiting for an exploit to happen. The best anti-forensic measures are not preventing the forensics process, but rather having no evidence appear when the process has already been done, like with amnestic systems such as TAILS when used properly.
Also see Daniel Micay about this same topic: https://www.reddit.com/r/GrapheneOS/comments/c0v33r/cellebrire_ufed_extraction_with_graphene_os/er8nari/
Depending on the person, who needs digital forensics tools or exploits? Use CCTV on the person or survey them where they can see their PIN code be entered. There are many accountable points of failure to take into account.
As for the brute forcing of the PIN, both devices have secure elements responsible for enforcing a rate limit on incorrectly guessing the PIN, which slows down and makes PINs above 6 digits impossible to bruteforce as long as this element is working. If the hardware element was exploited then the PIN would be bruteforced much faster and so a 8-10 word diceware passphrase would be needed to prevent the device from being cracked, but they are super impractical (unlocking your phone with a phrase like survive-decade-headfirst-bronchial$-tannery-uncorrupt-shape-Epileptic70-tarantula-habitual is tedious).
Fortunately files or other data on these newer devices can't be recovered when they are deleted, although in higher extraction levels like filesystem or physical extractions, there may be forensic artefacts showing that an app you used or file once existed. Depending on the apps you have installed, some may cache data about those files (for example, a file explorer caching an image thumbnail). Artefacts like these are contained entirely within the user profile so if you are that cautious, do most of what you can in a GrapheneOS user profile that you intend to delete every once in a while. That way even if someone DID extract, there should be nothing of value to extract as you would not be saving anything or making a history of yourself on the device.