Writing for television (or a series) is much more demanding and structured. It's excellent training for writing features. As for 'golden age' it depends on how you define 'golden'.
There are a lot of cheap-to-make reality shows and inexpensive documentaries that litter TV. Other than that, there are mostly cookie cutter programming. There are some innovative shows, but certainly not the diversity that were in the 60s, 70s and 80s. While there are more avenues to mount series and the cost of independent production has dropped, there are still significant obstacles for independent producers. These outlets are still not as well known as larger cable networks. And with concerns about net neutrality, some start-ups have been cautious launching into the market.
Significant risks were taken by studio execs to create programming like Star Trek, Gilligan's Island, I Dream of Jeannie, All in the Family, Murphy Brown, Dynasty, St. Elsewhere, Beverly Hillbillies, Quincy, X-Files, Man from UNCLE, etc. There were rewards. Programs broke ground and established models for many future programs. "Quincy" set the stage for "Diagnosis Murder", "Bones", "Crossing Jordan", etc. Similarly, "Dr. Kildare" set the ground work for "Marcus Welby", "Dr. Quinn, Medicine Woman", etc. The latter pioneering the female doctor roles. "Room 222" led to "Fame" which led to "Glee". "Trapper John" was a gentler version of "House". "Dragnet" set the foundation for police procedurals like "Law and Order". "Adam-12" and "Emergency" laid groundwork for "Miami Vice", "Starsky & Hutch" and the later "Chicago Fire", "NYPD", etc. Recycling the old into the new. Taking the buddy drama in a new direction was "Cagney & Lacey". "Red Skelton", "Lucille Ball", "Jonathon Winters" and myriad sketch comedies set the stage for "Saturday Night Live" and "New Kids in the Hall". Some programming has no modern equivalent and serve only as a reminder of who we once were "Waltons", "Andy Griffith Show", "Gunsmoke", "Rifleman", "McHale's Navy", "Laugh-in", etc.
Today, we have mostly copycat programming and documentaries. There are very few risk takers in major broadcast networks. And since they are owned by Microsoft (NBC), Disney (ABC) and other large corporations, it's not surprising given their vast libraries of older materials that the interest is in profitability rather than innovation.
For me, "golden" means when creativity and originality was greatest. In my opinion, the golden age of television is over. It is now the golden age of the cable series. Original programming by HBO, Showtime and Netflix are more original and bigger draws than the standard broadcast companies. Which is why a Comcast merger with Time Warner could be a game changer for start-ups and major broadcasters.