It's a case of "Nobody ever got fired for choosing X"[0]. No one would blame you for choosing React for a major project / new startup, but someone could definitely poke holes in choosing Svelte ("theres no package for X", "it doesn't scale", "we can't find devs that know it", etc.)
0 - https://www.quora.com/What-does-the-phrase-Nobody-ever-got-f...