I find spam calls do not leave messages or at least the majority do not...I get a half dozen or more a day on my land line. I simply do not answer a number I don't know or seems suspect. Very rare there is a message ...I call for messages and it is just dead air.
I rarely get spam texts ...a rare one here or there. I also do not get many spam calls on my cell...except for that Asian lady who calls frequently I keep telling her I do not speak any Asian dialect but she keeps calling me back.
I don't block any calls so not sure why I get so few on my cell..not complaining