"The NitroPhone combines security, privacy and ease of use with modern hardware. Long-term software updates until 2026 guarantee sustainability and a low price per time. The NitroPhone 2a is based on the high-quality Pixel 6a hardware and GrapheneOS, the most hardened Android for professionals. Gain full control of your smartphone without Google and Apple! Optional: Removed microphones, sensors and cameras make eavesdropping on the environment physically impossible. Phone calls are made with optional headset." https://shop.nitrokey.com/shop...

Using smart cards or USB tokens such as Nitrokey are a good option too because they are supposed to be secure against physical attacks and against password brute force attacks. In fact they use PINs which restrict guesses to three-or-so tries.