Basically Marvel Comics in need of cash sold off the movie rights to their most popular character Spider-Man and his gallery of villains gallery to Sony. However the gallery are sort of small fry in the greater Marvel world and one, Kingpin had evolved into Daredevil's chief nemesis and used in his movie and NetFlix series.
After the first Avengers movie proved the concept of the integrated universe to draw additional customers Sony wanted access to that cash so sort of leased back Spider-Man to Disney and the MCU but they still wanted to cash in on that Spider-Man gallery of villains and anti heros that they own. Meanwhile now that the MCU had their most popular character back they put him and just him, Tom Holland and Aunt May into Captain America and the Avengers without most his supporting cast to use in their Infinity Saga. While Sony gave us a couple of that Spider-Man gallery of villains in the two movies
However being real life and actors aging out of roles with the Infinity Saga done beside a few echos on Disney + miniseries it does look like the "its all connected" tagline is going away in favor of the branches of a multiverse introduced by the Ancient One in Avengers Endgame so Sony can publicise a Venom or Morbius connected to the MCU Spider-Man but any connections will be less than the TV series from least to most the Runaways and Clock and Dagger through the 5 NetFlix title characters to the Agents of S.H.I.E.L.D. and Agent Carter.