I only have three objections to the gendered pronoun in English.
1. It is often unnecessarily overly precise. The number of times I care about the sex/gender of the pronouned individual is much more rare than when I do.
2a. Using the masculine as the default leads to confusion at times or outright error. Is the equivalent of using zero as a default value for all integers when you don't know have the actual value.
2b. Using the plural they/them as the default for the ungender pronoun also leads to confusion and sometimes outright error. Although it follows a historical precedent of "you" becoming both singular and plural, I would point out that that's also why we have invented "y'all", to disambiguate, and it seems it would be clearer to have a singular ungendered pronoun.
3. The fad of the bespoke pronouns is basically just attention seeking toddlerism and socially destructive. Catering to that zeitgeist does nothing to reduce neuroticism that drives it.
We got rid of gendered nouns in English a long time ago. It is time for us to have at least an option for ungendered pronouns.