If the rot isn't extensive, you can replace the rotted boards. If it is extensive, then you might have rot in the structural parts and vinyl siding will just hide it. My house is about 100 years old, shingle-style. The shingles and the porch boards clearly have bits from different eras (with the porch boards, you can tell if you inspect the nails, with the shingles, it's the same thing, you have to be looking very closely). With paint covering everything, none of it is obvious (unless, of course, you're carefully examining the house for signs of older or newer parts) I think wood just looks so much better.

@Lisa M I hear you but when updating, one needs to also consider if there is any true architectural significance to what you are changing. Plus one needs to consider if the original was actually done well or was it just done to the trends of the time? Is preserving trends of the time of architectural value? Maybe. But we live in the real world with budgets, labor/material availability and new concerns impacting our decisions. Horizontal siding application requires expertise to avoid the risk of water leakage around windows, doors and other openings. Water finds its way and when it does it's damaging and can have adverse health impacts. Accommodating the horizontal cuts results in a lot more wasted material. So does today's enlightened awareness of sustainability and reducing waste secure a higher place on the priority list than preserving a look that recalls the trends of the 70's? Not sure if you are working with outside tradespeople on your shed, but finding quality craftspeople to do specialized work well is a lesson in patience, often literally years out, in my very active region. Specialized labor plus more material equals more cost. What are the family's other budget priorities? Does preserving a 70's trend outweigh saving for a child's education or your own retirement? To answer your question: "why would you buy a very specific 1980 house and try to use it as a springboard to faking the look of new build houses on your inspa lists." In the current real estate market, most folks buy a house based on location, cost and the ability to actually get your hands on a house in this crazy bidding market. The house style often has little to do with the purchase decision. May I point out that the OP has two, not four or five different siding styles on her home. Even FLW used two siding types on his own Oak Park house. If it's good enough for ole Frankie, I'll take it! Could he have bricked the entire house? Yes, so is that shake siding an arbitrary decoration? Who's to say what's an arbitrary decision on any structure? Some thought went into everything chosen. Not everything is precious on/in houses of their time. I just gutted a classic harvest gold bathroom. Should I have replaced it with the same since it is of the times of the house? No thank you. It had a good run and kuddos to the tile craftsperson who installed a shower pan that lasted 53 years. And BTW, thank ya Jesus for "James" Hardie. Had the company he established not pioneered fiber cement products, we'd have a lot more asbestos, rotting wood, black mold and ear piercing wood peckers waking us up at dawn. Big questions are interesting to ponder. Just not sure making assumptions about a poster on Houzz and the decisions they made is the place for it. Probably better to post your big questions as your own posts for comment. But...that's my opinion.

IMO remove the shutters , the posts need to be wood or composite material, yes the landscaping needs work . But first of all we need to know what you mean by modernizing. This os one of my faves for color with red brick. I think the fasteset way to devalue a house is to paint the brick just FYI This is not really more modern but a really nice look with the brick

I think a re-work of the shrubbery and hedge right of the round post is in order, along with removal of the shutters on the triple window if there is no variation in the brick color behind them. Have you considered replacing the trim shutters with some that at least appear as though they could actually function and close over the windows? Enlarge all exterior lantern lights to be 1/3 of the front door's height. Match garage door color to stucco or siding. If stucco is in good shape just keep it. You might match the column to the wall on the other side of the porch. Black or white both seem a bit stark to me. Does your gas pole light work? Sometimes I think capping those off and removing them is a better look. Is there another tree further out in the yard, more or less aligned with the triple window? You might consider planting an ornamental there.