Advice on UK/US/AUS citizenship

I (18m) have lived in the UK nearly all my life, born to Australian and Brit in the US, so have all 3. I am really considering renouncing my US due to IRS/other annoyances with ISA's and such. I don't really feel any connection to the US, I haven't been there since I was 3, and vaguely think I might want to go there in the future, but not until the current political situation is resolved. What are your thoughts? Is it worth keeping it just in case? Right now I see pretty annoying disadvantages for not many positives, though I am doing a degree in a defence related industry, so maybe that's a factor? Any thoughts.