Baptism and witnesses

Why is something as important as Baptism left to witnesses? Why aren't more people being baptized as an adult and only taking someone's word for it that they were baptized?

Without context, I am not quite sure what is behind your question about witnesses for baptisms.

When we baptize infants or adults, we seek to have witnesses on record. Those witnesses are in a position to verify, if need be, that the baptism did indeed take place.

Why not wait to be baptized as an adult? People have a need for baptism before they become adults (Psalm 51:5; John 3:5-6). Jesus’ instruction to “go and make disciples of all nations, baptizing them…” (Matthew 28:19) does not have age restrictions with it. Little children can indeed have saving faith in Jesus (Matthew 18:6; Luke 18:15-17).

When we understand the importance and blessings of baptism, there is every reason to baptize sooner rather than later. Witnesses can serve a valuable purpose in attesting that the sacrament was administered.