Because of course the One True Religion was bound to completely disappear within three hundred years and have to be restored scientifically hundreds of years later by theological archeologists and paleontologists.
At least the Landmark Baptists claim to go all the way back, as silly as that is.
When JESUS established His Church, He established a Spiritual entity originating with the Holy Spirit who abides in the psirit of every member of That Spiritual entity, not the orgs we focus upon today. That spiritual entity has remained and been growing for 2000 years, despite the blasphemies and heresies of men who create orgs claiming they represent the One True Church. Only the SPIRITUAL entity Jesus established is The One True Church, and it is not an org of any stripe.
The issue is how your beliefs line up with the the only wholly inspired substantive authoritative record of what the NT church believed.