NFL FA is a complex animal that doesn't always play out in terms of a completely rational, logical set of priorities and equations. "Semantics" help explain the best-available set of options NFL FOs have, including the Saints.
Winston is the best available FA QB that Loomis and co. have right now they can realistically get. That doesn't mean Loomis, in his private moments, hasn't said or told confidants or others haven't expressed desire that they wished they could afford to get somebody better. If the Saints FO could realistically afforded to pay Watson or even Baker Mayfield the contracts they wanted, they'd choose them over Winston because according to their calculations, both of them carry more potential significant upside.
You can twist that logic into saying, "Well, then I suppose Saints aren't completely sold on Winston to be the long-term guy". Well, sheet maybe thats right but right now he's the best option they can afford to pay and maybe they realize Winston is just a " decent filler" who can throw for 4,500 yards, 30 TD's for the next 2-3 seasons and just win 8-9 games, maybe 10 if he's lucky enough. Right now, some in the Minnesota Vikings FO probably wish they had a better overall QB than Kirk Cousins, but their sort of hamstrung by cap issues and the fact while Cousins is at best, decent, mediocre QB who'll never lead them to multiple SBs, he's still the best they have at the moment and likely for next season, too and its not realistically plausible their going to draft or sign a FA QB who's any better.
You have to have situational ethics or morality if you want to have any success as a corporate executive and that means sometimes going with maybe 70-80% of a sure thing then getting close to 100% with Brees because future HOF QBs like that don't come to franchises that often or under the strange circumstances that directed him to New Orleans back in 2006.
We've been spoiled by the fact Brees was go good and dominant for so long that we forgot what it was once like to have a flawed, often mistake-prone QB who could throw for 4,000 yards but at his very best, averages 8-9 wins a season and we have to accept he's our best available choice even in spite of his flaws and learn to live with it or try in vain to get something better.