I disagree. The 10 commandments are the objective benchmark, our school master, our tutor, the laws that tell us how we're doing in our spiritual growth. The two greatest commandments by Christ:
Mat 22:37 Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. Mat 22:38 This is the first and great commandment.
Mat 22:39 And the second [is] like unto it, Thou shalt love thy neighbour as thyself.
Mat 22:40 On these two commandments hang all the law and the prophets.
The first four commandments define love of God, the last 6 love of fellow man.
I do believe that you're correct in that physically trying to keep these commandments without spiritually living them isn't profitable. In that case we're just like the Pharisees, supposdely clean and righteous on the outside, but inwardly full of rot.
Mat 23:27 Woe unto you, scribes and Pharisees, hypocrites! for ye are like unto whited sepulchres, which indeed appear beautiful outward, but are within full of dead [men's] bones, and of all uncleanness.
Mat 23:28 Even so ye also outwardly appear righteous unto men, but within ye are full of hypocrisy and iniquity.
Those commands were the greatest given at that time. If those OT commands were sufficient, Jesus wouldn't have given us a New Commandment in John 13:34. But He did. It's interesting that in 1 John 3:23, we read,
"And THIS is His commandment: that we should believe on the name of His Son Jesus Christ and love one another, as He gave £us commandment.
This commandment swallows and replaces the previous "great" commandment.