I update this list from time to time. It overwhelmingly supports the premise that most of the founders of successful (or otherwise well-known) tech companies are typically in their 30s or older (and not ~18-22):

Paul Graham (31, Viaweb); Jan Koum (33, WhatsApp); Brian Acton (37, WhatsApp); Ev Williams (34, Twitter); Jack Dorsey (33, Square); Elon Musk (32, Tesla | 31, SpaceX | 27, PayPal); Garrett Camp (30, Uber); Travis Kalanick (32, Uber); Brian Chesky (27, Airbnb); Adam Neumann (31, WeWork); Reed Hastings (37, Netflix); Reid Hoffman (36, LinkedIn); Jack Ma (35, Alibaba); Jeff Bezos (30, Amazon); Jerry Sanders (33, AMD); Marc Benioff (35, Salesforce); Ross Perot (32, EDS); Peter Norton (39, Norton); Larry Ellison (33, Oracle); Mitch Kapor (32, Lotus); Leonard Bosack (32, Cisco); Sandy Lerner (29, Cisco); Gordon Moore (39, Intel); Mark Cuban (37, Broadcast.com); Scott Cook (31, Intuit); Nolan Bushnell (29, Atari); Paul Galvin (33, Motorola); Irwin Jacobs (52, Qualcomm); David Duffield (46, PeopleSoft | 64, Workday); Aneel Bhusri (39, Workday); Thomas Siebel (41, Siebel Systems); John McAfee (42, McAfee); Gary Hendrix (32, Symantec); Scott McNealy (28, Sun); Pierre Omidyar (28, eBay); Rich Barton (29, Expedia | 38, Zillow); Jim Clark (38, SGI | 49, Netscape); Charles Wang (32, CA); David Packard (27, HP); Craig Newmark (43, Craigslist); John Warnock (42, Adobe); Robert Noyce (30, Fairchild | 41, Intel); Rod Canion (37, Compaq); Jen-Hsun Huang (30, nVidia); James Goodnight (33, SAS); John Sall (28, SAS); Eli Harari (41, SanDisk); Sanjay Mehrotra (28, SanDisk); Al Shugart (48, Seagate); Finis Conner (34, Seagate); Henry Samueli (37, Broadcom); Henry Nicholas (32, Broadcom); Charles Brewer (36, Mindspring); William Shockley (45, Shockley); Ron Rivest (35, RSA); Adi Shamir (30, RSA); John Walker (32, Autodesk); Halsey Minor (30, CNet); David Filo (28, Yahoo); Jeremy Stoppelman (27, Yelp); Eric Lefkofsky (39, Groupon); Andrew Mason (29, Groupon); Markus Persson (30, Mojang); David Hitz (28, NetApp); Brian Lee (28, Legalzoom); Demis Hassabis (34, DeepMind); Tim Westergren (35, Pandora); Martin Lorentzon (37, Spotify); Ashar Aziz (44, FireEye); Kevin O'Connor (36, DoubleClick); Ben Silbermann (28, Pinterest); Evan Sharp (28, Pinterest); Steve Kirsch (38, Infoseek); Stephen Kaufer (36, TripAdvisor); Michael McNeilly (28, Applied Materials); Eugene McDermott (52, Texas Instruments); Richard Egan (43, EMC); Gary Kildall (32, Digital Research); Hasso Plattner (28, SAP); Robert Glaser (32, Real Networks); Patrick Byrne (37, Overstock.com); Marc Lore (33, Diapers.com); Ed Iacobucci (36, Citrix Systems); Ray Noorda (55, Novell); Tom Leighton (42, Akamai); Daniel Lewin (28, Akamai); Diane Greene (43, VMWare); Mendel Rosenblum (36, VMWare); Michael Mauldin (35, Lycos); Tom Anderson (33, MySpace); Chris DeWolfe (37, MySpace); Mark Pincus (41, Zynga); Caterina Fake (34, Flickr); Stewart Butterfield (31, Flickr | 36, Slack); Kevin Systrom (27, Instagram); Adi Tatarko (37, Houzz); Brian Armstrong (29, Coinbase); Pradeep Sindhu (43, Juniper); Peter Thiel (31, PayPal | 37, Palantir); Jay Walker (42, Priceline.com); Bill Coleman (48, BEA Systems); Evan Goldberg (35, NetSuite); Fred Luddy (48, ServiceNow); Michael Baum (41, Splunk); Nir Zuk (33, Palo Alto Networks); David Sacks (36, Yammer); Jack Smith (28, Hotmail); Sabeer Bhatia (28, Hotmail); Chad Hurley (28, YouTube); Andy Rubin (37, Danger | 41, Android); Rodney Brooks (36, iRobot); Jeff Hawkins (35, Palm); Tom Gosner (39, DocuSign); Niklas Zennström (37, Skype); Janus Friis (27, Skype); George Kurtz (40, CrowdStrike); Trip Hawkins (28, EA); Gabe Newell (33, Valve); David Bohnett (38, Geocities); Bill Gross (40, GoTo.com/Overture); Subrah Iyar (38, WebEx); Eric Yuan (41, Zoom); Min Zhu (47, WebEx); Bob Parsons (47, GoDaddy); Wilfred Corrigan (43, LSI); Joe Parkinson (33, Micron); Aart J. de Geus (32, Synopsys); Patrick Byrne (37, Overstock); Matthew Prince (34, Cloudflare); Ben Uretsky (28, DigitalOcean); Tom Preston-Werner (28, GitHub); Louis Borders (48, Webvan); John Moores (36, BMC Software); Vivek Ranadivé (40, Tibco); Pony Ma (27, Tencent); Robin Li (32, Baidu); Liu Qiangdong (29, JD.com); Lei Jun (40, Xiaomi); Ren Zhengfei (38, Huawei); Arkady Volozh (36, Yandex); Hiroshi Mikitani (34, Rakuten); Morris Chang (56, Taiwan Semi); Cheng Wei (29, Didi Chuxing); James Liang (29, Ctrip); Zhang Yiming (29, ByteDance);