Do we really have to kill people who leave Islam

salam to all.

I have generally heard that it is acceptable to kill some1 who leaves Islam. ofc people who leave Islam to bad mouth muslims and the reliigon or people who leave Islam for money wealth etc are understandable but what about those people who leave Islam for their own reasons. I mean they will become kaafirs but isnt it Allah's job to punish kaafirs on the day of judgement ?? plus who knws people who leave Islam may also revert back to Islam

a little clearing up on this matter would be really helpful b/c I don't think we should just kill about any1 who leaves Islam & I feel neither would prophet Mohammad [pbuh]. My thinking may be wrong which why I would like to be corrected :statisfie