we resurfaced most of the walls and some cielings in our home over 10
years ago with drywall mud. it still looks perfect today.

some walls were water damaged, others like yours had been papered. the
water damage occured years earlier when a previous renter got evicted.
the last thing he did after not paying rent for 3 months was turn on
all water, close and clog all drains..... geez what a jerk.

clean walls of all paper, lloose anything, undercut cracks fill and
tape.

paint everything with BIN primer sealer for best adhesion, then a thin
coat of drywall mud, with brush finish to cover minor irregularties.

then paint as usual. one of the best home fix ups we did. the walls
were so bad we had considered gutting.

its a DIY project, pick a small wall and give it a try