Scheveningen

It would be, no question about it. Living like 95 years you already watch your entire fam and everyone you love wither to dust. Only way immortality would be tolerable is if you took a eastern religious mindset like Taoism suggests where you actually stop thinking about anything, and while being focused on helping others for your self worth, your literal life and belief system revolves around a 'Go with the flow' mentality. That or reach enlightenment.

More likely a person would become a catatonic emotional wreck within 300 years of outliving everyone they love.

Turns out the truth of impermanence is extremely sad (That we all are doomed to die) but the alternative is much worse contrary to popular opinion

I'll take dying with my sister/someone I helped a lot in my life clutching my hand by my bedside.