Typical jelly & jamrecipes call for close to 1:1 fruit to sugar. E.g. ¹Ball mason jars strawberry jam recipe calls for 7 cups sugar to 5 cups strawberries. Martha Stewart calls for 3/4 cup sugar for every cup of juice² in making jelly. The Joy of Cooking (44th printing 1988)notes that "Store-bought jellies, according to law, must have at least 45% fruit and 55% sugar". Etc.

¹https://www.ballmasonjars.com/blog?cid=classic-strawberry-ja...

²https://www.marthastewart.com/1127955/basic-jelly-recipe

³ ISBN 0-02-604570-2, Joy of Cooking, Irma S. Rombauer, Marion Rombauer & Becker, page 832

You can make jam with a lot less sugar. I make my own strawberry confiture at home and use about 5% sugar, plus pectine and sweet lemon juice.