Math.random of JavaScript is  PRNG (rather than TRNG) which uses algo (depends on browser)  designed  for general-purpose randomization  (needed for example at game development)   rather than to produce true randomness suitable for cryptographic. So entropy generated by JavaScript (and subsequently SEED phrase)  is less secure than that one generated by TRNG in hardware wallets, sai in Passport 2  which utilities Avalanche diode as a source of randomness.