The answer to that question is the same as, why do I need a child seat?  Why do I need to lock away cleaning supplies?  Why do I need a fence around my pool? Why do I need to close my front door?  These are all things we do to keep our child safe.  While most of these measures seem like common sense, we are often dependent on others to help us.  I am not a car seat expert.  When I intend to buy one, I read the reviews and make sure they are approved by the DOT.  I am also not a chemist so I rely on the labels to make sure that if I leave the stuff standing around and my child takes a gulp it won't kill her.  With baby gates you don't have the luxury of labels.  You have to rely on the manufacturer to adhere to the ASTM (American Society of Testing and Materials) standards.  Most independent small companies that populate the handmade marketplaces don't even know what these are, much less build their gates to standard. You go to Ebay, Amazon, Etsy and read the reviews and they tell you that the gate looks great or was delivered in a nice box.  Not many will tell you if a gate actually did it's job.  "My two year old ran full tilt at the gate and smashed through it like the Danes sacking a Saxon fort."  "My 18 month old toddler made Tom Cruise look like a novice when he reached through the slats and flipped the latch."  "My 12 month old baby girl scaled the 24 inch baby gate like a sherpa on his way up Mount Everest."  At Oak Grove Woodworks we consider all this.  Your child will not be able to smash through our gates.  If he does you should consider buying him a cape and thinking of a cool name.  Our gates are 33 inches high and have the latch facing away from the room.  Which means your 2 year old is really five and somehow you just woke up from a coma.  There are no hand or foot holds that would enable even the most adventurous toddler from climbing up our gate, unless he has a rappel line and a harness.  All in all, our solid wood and iron gates are constructed with these contingencies in mind.  That still begs the question why do I need a gate  Children are curious and once they start to crawl, very mobile.  No one is going to turn their living room into Alcatraz.  But unless you have eyes in back of your head, motion sensors, trip wires or any other high speed device that you'll only find in the Louvre around the Mona Lisa, you might want to consider one of our gates.  Having a gate at the top of the stairs, separating the play room or in the doorway leading to the basement will give you the peace of mind you'll need when you don't always have eyes on your child.  Of course, there is always the option of a leash and flexicuffs but those methods are still frowned upon by child services.Now that you think a baby gate might be a good idea, here are some of the things to look for.  Stability is the most important.  You want your child to be contained and a solid gate that can withstand a charging baby rhino. Ours do that.  A secure gate needs to be safe.  There should be no foot threshold to trip over. This is something you will find in all gates that are pressure mounted.  There should be no exposed nails or screws, sharp corners, wooden splinters, big gaps between the bars or anything else that can cause harm to your child.  You don't want your child to not fall down the stairs, but instead get their head stuck between the balusters of the gate.  Here are some pictures I found online of baby gates.  Mind you these are sold on Etsy, Custom Marketplace and other recommended sites on the web, including the 5 star reviews.

 The baby gate is very sturdy and well-made. It was also finished very quickly. Highly recommend! "We finally got it!! So pretty. Really love it. Can’t wait to use it! Also — Thanks for wrapping it so well, the delivery guy just chucked it down the stairs to our patio!!" Exactly how we envisioned! Very satisfied. 

Communication was quick and we were able to review and approve the design. Ordered, shipped, and installed in less than a week. Highly recommend. 

Aside from the reviews its also nice to brouse the "about page"  on these sites.  Mostly you are dealing with self taught woodworkers, a hobby turned into a business and so on.  Would you trust an amature to build you a car seat for your child.  You might ask how hard can it be?  How hard can it be to wire your house, change the brake in your car, or connect a gas line?  Its not hard, it's just hard to do it right.  At Oak Grove Woodworks our gates are build by a trained master carpenter.  I spend 10 years learning the craft.  That is the equivalent of becoming a doctor and I continue to learn.  That is why we build our gates using traditional joinery, not nails or kreg screws.  It comes down to, you get what you pay for.  We make sure we use solid reclaimed oak or maple, steel bars, forged iron latches and non toxic finishes on our gates to make them as safe for your child as we can.  Ultimately it is your choice what gate you will buy, but can you put a value on your childs safety.