It is only in the last 40 yerars or so that the norm in US politics has been nominating conventions with the nominee either certain of selection or so close to it that there is no real contest.

Previously contested conventions were the norm. At least that made the conventions more interesting. I am not sure that taking a few ballots to come up with a nominee is going to damage a party.

The only thing damaging to a party is if the convention fight is so long and bitter that it proves that the party is badly split. The 1924 Democratic convention, when William G. McAdoo (backed by rural, southern and western delegates, who were dry on prohibition) and Alfred E. Smith (urban, Catholic and wet on prohibition) battled it out for more than 100 ballots before the weary convention settled on a compromise candidate. Of course the severity of the deadlock was made worse because a two-thirds vote was then required to nominate.