What will I lose if US employer switches me to working for a foreign company?

I’m a dual citizen having grown up in the US, but working and residing outside of US for 20 years. I have worked for my US-based employer for 10 years during which time I’ve been paid in the US with basically the same benefits as my US-based colleagues (although I don’t have US health insurance). For legal reasons my employer now wants to pay me in the African country where I work. I have issues with this due to much higher taxation rates here and the presumed loss of my retirement benefits since these were all through my US employer’s benefits program. I’m also wondering what else I will lose in terms of long-term protections/benefits things like disability, social security, workman’s compensation? Is this correct? and is there any other things I will lose if my employer goes ahead with this?