Digne joined Aston Villa on Thursday in a deal rising to £25million after falling out with Toffees boss Benitez.
The left-back took a parting shot at Benitez as the transfer went through, saying on social media: “Sometimes it only takes one person from outside to destroy a beautiful love affair.”
Benitez, speaking for the first time on Digne’s departure, said: “I am the manager and I take the responsibilities of my decisions.
“It is to think of the team and the future of the club, and we have to move forward and think about that.
“If you’re in a boat and someone is not rowing with the strength that you are expecting then you have to make your decision.
“The realities are when you have a player that is thinking to leave and then you have an offer, a possibility.
“We brought in a couple of good young players, hungry players. I’m sure they will be good now and better in the future.
“It’s something positive for the club to sell a player who will be 29 years of age this year and bring in players of 20/22 and in positions we needed to balance.
“We are balancing the squad, improving the competition, and economically it is good business.”
Anwar El Ghazi made the opposite journey to Digne on Thursday by joining on loan from Villa for the rest of the season.
The Dutch winger became Everton’s third January addition following the arrivals of full-backs Vitalii Mykolenko and Nathan Patterson on permanent deals.
“It was part of the deal with Digne when we started the conversations,” said Benitez, speaking ahead of Saturday’s Premier League game at Norwich.
“We were thinking about the Covid situation, possible injuries, the Africa Cup of Nations with (Alex) Iwobi away and bringing in someone with quality who could give us different options.
“It is good because it is a loan with an option and the player has to prove himself.
“We can see him, so I think it’s a win-win situation. If he’s doing well everyone will be happy and he has told me he has come to fight and show his level.”
Everton have dropped to 15th in the table after managing only one league win since the end of September.
But they have games in hand on most of the teams directly above them and Benitez says his squad is now close to full-strength.
Only midfielder Tom Davies, sidelined after hamstring surgery, is set to miss out at bottom-placed Norwich, although Benitez said there “may be one Covid case” in his squad.
“We have players coming back, still not fully fit and people have to understand that match fitness comes with games,” he added.
“We are quite confident that we have people coming back, and if we have some wins we will be in a much better position and play the way we want to play.”