Is there a reason to make home made glucose syrup?

Every candy recipe calls for glucose syrup, but I cant find one in my area. I can make inverted syrup before cooking, but does making syrup and adding it to the sugar is the same as adding sugar (amount of sugar from recipe plus amount of syrup) + acid without intermediate step?

No, they are not the same.

While adding sugar, water, and acid directly into your main candy pot will create some invert sugar during the boil, the conversion efficiency is low and unpredictable compared to pre-making an inverted syrup. According to a detailed breakdown by Taste of Artisan, standard acid hydrolysis requires specific time and temperature control to reliably break sucrose down into glucose and fructose.

Furthermore, glucose syrup and invert sugar behave differently in confectionery. As explained by the culinary chemistry resource Science of Cooking, commercial glucose syrup contains long-chain carbohydrates called dextrins, which are highly effective at blocking crystallization because they physically tangle up the sugar molecules. Invert sugar consists of simple, short-chain sugars that do not have these long dextrin chains, meaning it behaves differently in a boiling candy batch and is notably sweeter.

If you just dump the raw sugar, water, and acid together without that intermediate step, you won't invert enough molecules fast enough to stop grainy crystallization, and you risk making the candy intensely sweet or throwing off the final moisture balance.