This reminds me of a long phase my mother seemed to be stuck in. FWIW, nobody would have ever described her as a hoarder, and left to her own devices she does keep her house spick and span - it does help that her home is quite a new building, and that it is three-bedroom two-bathroom for just herself - and she is conventional as far as housekeeping goes.
During her unhappy marriage to my father, however, which was spent in a remote farmhouse with no municipal rubbish collection, she did develop a notable problem with hauling home unnecessary shopping. The OP's description of desiring a specialised piece of equipment for each task was certainly something my mother did - and she still does this: last time I visited, for instance, she proudly showed me a gadget which is used to turn zucchini into spaghetti-shaped strings (doesn't really work even for that narrow purpose). It chimes with a need inside herself to be organised and well-supplied, and not to be seen to be just 'making do'.
But no spending category has really been beyond her range - electronics was safe, perhaps? She overbought: clothes for herself, clothes for one of my younger brothers, bedding, kitchen gadgets as mentioned, cookbooks, New Age paraphernalia (drums, crystals, massage tables, Bach flower essences, essential oils, books, calendars, jewellery), artwork, knick-knacks, magazines ... A recent visit saw her bringing out her bathroom toiletries collection - expensive shampoos, conditioners, creams, all these lady potions - which she amusedly noted were all completely surplus to her requirements ... I only wished I could have carried them all home with me so that I could be set up for the next 10 years! (wasn't practical to do so, believe me, I did the maths). Many of her belongings are items of beauty and all are well-cared for and stored attractively with plenty of negative space.
In her case, eventually she did tire of going to her stressful full-time job, which she retired from at age 63, and that has stanched the inward flow. Also, it is au courant to cull, and she is falling in with the times. Maybe she has an eye to the horizon, too: one day in 10-15 years she will need to downsize quite considerably, and that task is best done at a leisurely pace. She is a pretty sensible person. She is also infallibly generous, so responds well to the idea of passing things on to charity.
Depression was a factor; the ramping up of consumerism in the late 1980s may have triggered a pre-disposition to buy too much ... but she always had the flip-side, the disinclination to cull: even in the '70s, we would always have a spare bedroom full to overflowing (and which we as children loved, it being like an Aladdin's cave).
Identity has been a huge factor: so she is a quality person, with quality taste, as reflected in her belongings - again, that 80s ethos. I am sure she despairs of my comfortableness with shabbiness as a mark of lacking self-respect, or something along those lines.
Certainly my brothers and I have been shaped by all this. One brother has kept, for several years, extra stuff spread across two storage units. The other has a large farmhouse of his own with belongings swelling out onto the verandahs, and buys in new stuff on the internet rather than maintaining his existing stockpiles. Myself, I find this all endlessly fascinating; I am a longstanding minimalist and my family is used my clarion cry 'I can feel a declutter coming on!'
Coming back to the OP: I can feel your love for your wife in your words, and feel sure that some kind of appeal to her better self will be effective in the medium term.