My suggestion for now, no need bro, i had seen ur speedtest result, ur getting full upload & download speed as per plan, if upload & download speed reduced & in future ur upgrade to higher speed plan & need more device means go for 5ghz modem
By the way 5ghz (5g) modem support both dual 2.4ghz (4g) & 5ghz but issue is 5ghz signal coverage is very less distance & moreover 2.4ghz signal coverage little bit is drop in 5g modem compare to normal 2.4ghz modem
I had tested in my bsnl net link 5ghz modem & railwire 2.4ghz modem,jio 5ghz modem, getting very good signal coverage in railwire 2.4ghz old modem only