Showing my age here, but as someone who grew up in the '90s and '00s I have seen quite a lot of rapid change in the retail landscape in my home nation (the UK). With the continuous squeeze on real-term wages (that is to say, the value of the money people are earning versus the cost of goods and services) brand loyalty should not be a top consideration for anyone who is not already extremely financially comfortable, in my opinion.
According to Circana via the Retail Times (accessed 17 June 2023) private label brands in Europe constituted about 38% of sales. This is quite high but I think we can all be doing better. The fact of the matter is private label brands (i.e. store brand or brands developed by chain grocery stores/supermarkets to be exclusively sold within them) do tend to do just as good a job as 'the real thing' and even when this is not the case, one can always factor in the price difference. There are also some very impressive brands that are not specific to chains out there, but I find those to be few and far between (see my recommendation for Hair & Scalp shampoo at the bottom of this article).
Of personal anecdote recently and as an avid Lidl shopper, Lidl grocery-related brands tend to cost about 50% of the equivalent name brand on the shelf (protip: price per whichever unit is applicable is often listed in fine print below the product price). This is not Lidl scalping the product prices either as big brands are typically on, or almost on, par with the likes of the more traditionally established supermarket chains of the UK (Tesco, Sainsbury's, Asda and Morrisons).
We should all have a few luxuries. I personally am partial to Red Bull having drank plenty of cheap 'ES' (Euro Shopper energy drink) in my youth, and despite the questionable advertising choices of companies such as P&G lately I will not be giving up my Gillette Mach3 razor easily. This taken into account, though, we should also be questioning ourselves with every purchasing decision whether it is worth it to spend the extra or save a buck: I think if you try the latter a bit more often you will be pleasantly surprised.
If you happen to live in the UK, here are some of my personal price/performance recommendations for big brand alternatives as of 2023: