Best Dialer Platforms for SDRs to Improve High-Quality Phone Number Connections in the US

Which dialler platform would be great for my Sdr’s forg etting the high-quality phone numbers? I am right now using Apollo, but I am finding very low connect, especially in the US because most of the calls are redirected to voicemail. So do you guys have any suggestion on this? how I can approach this. My GTM stack is smartlead, custom LinkedIn Automation, Apollo for data, LinkedIn sales, aircall for dealer