Will my 1099 income for 2021 be used just like W_2 Earning for social security.

Hi. No. Social Security taxes are not withheld from income reported on a 1099 form. Income reported on a 1099 form is only considered as earnings for purposes of Social Security benefit calculations and the Social Security earnings test if the income represents self-employment earnings. If it does, then the countable amount of the self-employment income is the net earnings from self-employment (NESE) that's reported on Schedule SE of the person's tax return.

Best, Jerry