Modern Pixel phones have a TPM-like device that protects against brute-force attacks. Assuming the pattern is non-obvious, an attacker has 20 attempts before the supplementary key material is wiped and the encryption key is lost.

It's theorerically possible to use side channel attacks against the security chip to bypass this, of course, but that requires opening the device and some very precise, damaging operations, assuming the attacker has a known-working side channel attack in the first place.