I don't think Britney has a problem with likability, she's always been likable but she hasn't been able to translate that to relevancy in 2016. She's not relatable to younger audiences either because she's a single mum who happens to be a popstar.
Not that relatability is even a requirement to be relevant to younger audiences. People like Beyonce and Kanye use their relative unrelatability to their advantage by being aspirational.
Beyonce is a mix, actually. She has a big aspirational persona onstage but she still does relatable topics like infidelity. I may be wrong, but Kanye is relevant but he isn't as big musically anymore as he used to.
We can all relate to Britney because we follow her, but in the past few years, she hasn't put herself out there enough for the newer generation to appreciate the relatable aspects of her. Artists like Taylor make big efforts (most of the time cringey) to look relatable to the average Tumblr girl and it worked. Most importantly, it translates to their music.
I love Glory, but I'd love to see a Mood Ring direction too because it's the most relatable song she's had in a while. Melanie seems to understand Britney the persona, which translates into the lyrics and I'd love her for B10.